Portland/Vancouver Backgammon

We had a perfect 8 person bracket for today’s tournament. Newcomer Nathan entered the actual tournament, and Kitster came along a bit later to play some side games, which worked out great! And finally, we got to meet Sharon’s father, Anthony, who was in to visit and got dragged into a few games as well. It made for a lively afternoon of play!

In the main bracket, Bryan marched ruthlessly to the first place spot. Second place went to Sharon, who foolishly took a cube from me in our first game but then went on to win over and over again. In the consolation bracket, it came down to me versus Joel, and I was able to hold him off. We wrapped up play by about 4:00, although Bryan and Tim were still playing a one-off match when I left.

Results for everyone are as follows:

Player	Initial Elo Rating	Matches Played	Matches Won	Final Elo Rating
Bryan	1523.2	3	3	1573.05
Mark	1524.2	4	3	1546.40
Kevin	1543.0	3	1	1521.33
Joel	1513.6	4	2	1514.54
Sharon	1473.0	3	2	1496.73
Tim	1495.3	3	1	1475.85
Nathan	1500.0	2	0	1471.05
Julie	1452.3	2	0	1425.74

The cooler weather and grayer skies were good for backgammon turnout – we had 8 people for our second attempt at meeting at Bushwacker, a perfect bracket. Apologies to Bryan, who showed up mere minutes after I got us started. We’ll get you next time!

Martin and Mark F were again matched in the first round, which I swear was random, but if it happens again next time I might re-roll the lineups, because that’s too much good luck for the rest of us. Kevin and Sharon made the trek up again from Coos Bay; and we had one newcomer, Tim, from far off Vancouver (aka my hometown). Michael and Sara rounded out the bracket.

Personally, I played Kevin, then Sara, then Mark F. If you’re thinking through the logic of the bracket, you’ll know I therefore finished first or second. Hold that thought in suspense for a moment to consider this, my biggest blunder of the day:

Mark F took a picture for later, and graciously sent it to me with some commentary. I’m black in this picture, and leading 3-1 in a 5 point match. 2 away-4 away, and so I know for sure if I double and he takes, the cube is coming back to me on the next move. I had been going for the gammon, but had to leave a blot on the two point, and Mark F rolled a 1, blowing my gammon chances, or so I figured. So, my line of reasoning went I’m still a strong favorite to win the game, if I double he’ll probably drop and I’ll get the Crawford game. What could go wrong?

Well, I’m not a strong favorite to win, I’m barely over 50%! GnuBG says the move before (when I had 2 on the two point and 3 on the three point), I was 87% to win and 68.2% to gammon. After the disaster roll of 5-2, I drop to 51.4% to win, 23.8% to gammon! I was right about losing a lot of gammon potential, but the overall win chance was way worse than I was thinking -because what happens next, most likely, is that I’m forced to hit a blot on the one or two point, red hits it again sending a second piece back, and giving red a good chance to win! Easy take for Mark F, and a huge blunder for me!

Nevertheless, sometimes the weaker player gets lucky. In this case, after a few enter/hits/rehits, I got a double 5 that brought my back checker from the 23 to the 3. Mark F still had blots on the 1 and 2, and four slots of his home board covered by that point, so most rolls would leave me with a double shot. Imagine my relief when I pulled out a double 6 at that point! Pro tip of the day: during the bear-off, it’s hardly ever wrong to roll doubles.

In the consolation bracket, after some initial confusion on my part, Michael held on to take 3rd place. We wrapped up tournament play a bit after 4:30, which was good for me, as I had to pick my wife up at 5:00 – so as far as I was concerned, a perfect tournament!

Overall results and impacts on Elo scores:

Player	Initial Elo Rating	Matches Played	Matches Won	Final Elo Rating
Mark F	1604.6	3	2	1606.37
Kevin	1584.6	2	0	1543.04
Mark	1457.0	3	3	1524.18
Michael	1486.1	4	3	1519.76
Martin	1524.6	2	0	1495.75
Tim	1500.0	4	2	1495.33
Sharon	1487.4	3	1	1473.00
Sara	1478.3	3	1	1465.28

See you all next time!

-Mark

You know how many people it takes to play a match? Two. We had one more than that show up, since my youngest consented to come along. But Martin & I played a couple of 9-point matches anyway. I won the first, and not to brag, but I won a match against Martin! So that was cool. He, naturally, made up for it in the second – but it was a great match! We traded games for a few, then he got me on the ropes. I survived the Crawford game to get to an 8-5 deficit. Then I won a doubled game to get to an 8-7 deficit. Double match point game at one point had me looking like a strong favorite; but I misjudged. I thought I was far enough in the race to not bother hitting him on the ace point, and Martin took a couple of big rolls to come back and win the second match! Ah, well, live and learn: always hit on the ace point if your opponent doesn’t have a closed board! Unless you shouldn’t for some other reason, of course.

Anyway, the cider house seemed like a lovely location, although it was a big warm on this particular day. Apparently, don’t schedule tournaments in August, or not the day before total eclipses, or something.

Martin wanted to have a third tie-breaking match, but I begged off to drive to Madras, and let me tell you, seeing the totality was worth the effort. We even made it home afterwards – eventually. So if you have the choice between playing backgammon and watching a total eclipse, I recommend taking the eclipse. But bring your board, because there’s plenty of time during the buildup to get a game or three in.

-Mark

We had a pretty good turnout – 7 people total. Initial cast of characters was the regulars: Mark F, Nick, Mark S, Paul, and me. Mark S charmed the gentleman who had taken “our” table before we arrived into moving over one, and received instant karma in that he took the box initially. But then he proceeded to hold it for a full rotation of the field!

About that time, Gints arrived, and so Paul and I split off to play with him at a lower stakes table. Jim showed up shortly thereafter and eventually got suckered into joining the higher stakes table.

The gentleman who Mark S had charmed off chatted about literature, politics, and jokes that were funnier in other languages while we bent over our boards. The lower stakes table was pretty evenly matched – Gints held the box for quite a few games at first, but then we settled into a cycle of pretty regular turnover. Ours broke up just before 5, but the high stakes table was still going – Mark S continuing to reap the karmic benefits of his charm offensive.

Here’s one position that came up that lead to some discussion about the right move. I am black and in the box, and offered a double. Was I right to do so? Would you take?

According to both GnuBG and Extreme Gammon, black is about 70% to win 70.6% or 70.4%, depending which you ask. But it’s a very minor error to double! By doubling, I gave up 0.005 in equity. Note that the gammon chances here are very low, under 1%, and so the Jacoby rule doesn’t provide a rationale for the double. So this is a No Double/Take situation. I forget what happened over the table, but I believe there was one take and one drop.

Gints took a few more pictures, and if he sends them to me I will update the post with any other interesting ones.

Meantime, we’re up again next weekend for a tournament – low RSVP count so far but there’s a week to go. See you there!

-Mark

Not surprisingly, I was playing some backgammon against the computer today. What was surprising, to me at least, was the following position came up that got marked as “doubtful” by GnuBG:

Now, I didn’t even think about this one, clearly the right move is 11/7,10/7 and making the 6 prime. But GnuBG said no, 10/6, 9/6 is better. Huh?

GnuBG says 10/6, 9/6 has equity +0.788, 11/7, 10/7 has equity +0.715; a difference of -0.073 and so a blunder! Extreme gammon rates it similarly, 10/6, 9/6 gets +0.797 while 11/7, 10/7 gets +0.736, a difference of -0.061 and again a blunder!

It gets worse for me. After the next exchange of rolls, I was at the following position:

D’uh – clearly 9/2 is the right move. But no, GnuBG says 7/2, 5/2!!! 9/2 has +0.728 equity, versus +0.792 for 7/2, 5/2, a difference of -0.064 and so another blunder! Extreme gammon agrees again.

The key here is the cube. With the cube in the middle, the moves I actually made are the correct moves. But the cube has already been offered and taken, and that makes a difference. I no longer have the option to double red out after a rough roll, I have to take what I get – and if I get something bad red has the redouble.

As it happens, what I got was a 5-6 on the first roll bearing in against the men still on my one point, forcing me to leave two blots. Red rolled a 5, putting me on the bar, I danced, and then got redoubled out. So it really could have worked out better for me. But the main thing was these back-to-back positions where the difference in correct play depends so much on the cube position.

This table shows the winning chances for each move for the first position, per GnuBG:

	Win	W g	W bg	Lose	L g	L bg
11/7, 10/7	0.811	0.129	0.005	0.189	0.005	0.000
10/6, 9/6	0.835	0.146	0.005	0.165	0.005	0.000

And this is the equity, depending on who owns the cube:

	Equity Cube in Middle	Equity, Red’s cube	Equity, Black’s cube
11/7, 10/7	+1.000	+0.715	+1.000
10/6, 9/6	+0.934	+0.788	+0.978
Difference	+0.066	-0.073	+0.022

Very similar charts for the second position:

	Win	W g	W bg	Lose	L g	L bg
9/2	0.824	0.115	0.004	0.176	0.005	0.000
7/4, 7/3	0.833	0.145	0.006	0.167	0.005	0.000

	Equity Cube in Middle	Equity, Red’s cube	Equity, Black’s cube
9/2	+1.000	+0.728	+1.000
7/4, 7/3	+0.925	+0.781	+0.970
Difference	+0.075	-0.053	+0.030

I find it also interesting that the drop in equity for leaving an indirect shot is a lot lower when black owns the cube in both positions as well. I think either of these would make a good “quiz” question for Phil Simborg. Having them back to back like that in a game definitely made me stop and think about the value of owning the cube!

-Mark

We had an incredible turnout at Occidental Brewing this afternoon – 20 players! That is, in fact, a new record. There were a lot of newcomers or people returning after a long absence as well – I think 7 or 8 people I had not had the pleasure of meeting before.

We caught the management off guard – I should have scoped out the location earlier and I would have learned that they were a little on the smaller size, in the area we took over. Probably should have given them a head’s up, but Sara and others smoothed some feathers with the staff and once we got running, it went very smoothly. If we go there again, we’ll warn them, and probably move to the upstairs space, which is (I’m told) a little larger (I never made it up there today). Martin assured me that this is the best brewery in Portland, even though it is somewhat out of the way for people, based on the majority of comments I got.

Being such a large group, I divided us up into two brackets. You would think 20/2 = 10, but with the chaos of filling in the brackets as a few stragglers rolled in, we ended up with 9 in the A bracket and 11 in the B bracket. Oh well!

The “A” bracket ended up in a newcomers show-down. Karen beat out William for 1st, and Billy won the consolation bracket. The “B” bracket went to the established crew, with Nick beating out Gints for the big prize. I squeaked out a win in the consolation bracket, mainly because Mark F left “early” – I would have had to face him again, but he didn’t want to stick around another half hour or so for the $10 entry refund that went to third place. So: payday!

Greg made the suggestion that the consolation bracket should run 3 point matches instead of 5 point matches, in order to wrap up a little faster. By definition the consolation bracket starts later, and so it was running long. Thanks for the suggestion, Greg, we will definitely do that next time!

The other big thank you goes to my daughter, Kira, who took over the clipboard while I played and helped keep the tournaments running smoothly. What a great Father’s Day gift, eh?

All in all, we did manage to finish the tournament by 6, although Nick and Bryan were observed playing a money game as I headed out. Some people never get enough, I suppose. If you want more, we’ll do it again next month at Great Notion, on July 16th. I’ll call and warn them first!

Player	Initial Elo Rating	Matches Played	Matches Won	Final Elo Rating
Mark F	1542.6	4	4	1604.62
Karen	1500.0	4	4	1568.85
Nick	1500.0	3	3	1554.27
Billy	1500.0	4	3	1530.34
Bryan	1544.6	3	1	1523.25
Mark	1534.4	3	1	1518.88
WIlliam	1500.0	3	2	1517.10
Joel	1500.0	3	2	1513.56
Noah	1500.0	3	2	1513.53
Mally	1500.0	4	2	1506.43
Greg	1500.0	4	2	1500.15
Paul	1508.5	3	1	1492.50
Gints	1469.3	3	2	1491.31
Karla	1500.0	3	1	1483.08
Martin	1500.0	2	0	1468.08
Donnelle	1500.0	2	0	1466.07
Kristin	1500.0	2	0	1465.10
Julie	1502.8	3	0	1452.32
Sara	1482.1	2	0	1450.28
Justin	1480.7	2	0	1445.35

We had a record turnout for the Chouette this month – 9 people! I was hoping we would break into double digits, but maybe next month. Mark F, fresh off his second place finish in the Chicago Open Master’s, was feeling peppy going in, and he was in charge of the “advanced” board. He asked me not to mention how he did, you can draw your own conclusions there. Julie took over the “beginner” board, where she held the box for a long, long time against newcomers Tanya and Ted. They had a lively time with lots of discussion about the best moves at each point. That left Gints and I on the “middle” board, which, if you count carefully, does not equal a chouette. But we had fun anyway.

Gints and I are pretty evenly matched at backgammon, and we ended up taking pictures of a LOT of positions for later analysis. The ones I took, I have to say, most of them were not that close – I was offering doubles much too early and accepting them much too late. But occasionally, they were interesting, as in the following:

Here I’m red, Gints is white, I have two on the bar and am being redoubled. Would you have offered that double? Would you take in my place?

The race is actually pretty even, he’s up 132 to 143. My risk is, nothing is especially holding him back at this point. He has 4 and 6 to hit my blot in the outfield, worst case scenario is bring the back checker around. Seems like a pass to me, and it is. In fact, it is too good to redouble! Winning chance is at 76%, but 44% is gammons. GnuBG says no double has equity +1.117, XG says +1.141. I’m about to get buried here, and I took the chance to drop. If you don’t think about the gammon chances, it seems like a close call, but the majority of the losses are gammons, and since the cube has already been turned, they count.

Anyway, a good time all around – we’ll do it again next month!

-Mark

We’ve got the next few Chouettes & Tournaments on the calendar – check it out:

Chouettes will be on the second Saturday of each month through August – so June 10th, July 8th, and August 12th. They will all be at Lucky Labs on Hawthorne – that’s 915 SE Hawthorne Blvd if you want the actual address. Turnout has been pretty consistent so far, I hope we will build it up to be able to consistently have two tables going by the fall. Play starts at 1:00 and goes until 5:00 or so, depending on when people fall out.

We will have the June tournament on the 18th at Occidental Brewing, 6635 North Baltimore Avenue, starting at 1:00. Format to be determined – I’m thinking we’ll probably go back to a single double elimination bracket unless the turnout is pushing 16. Last time around, we moved it up to 5 point matches, and no-one complained, so we will likely do that again.

For July, the tournament will be on the 16th at Great Notion, 2204 NE Alberta St #101, again starting at 1:00. Same caveats as for June. Have you noticed a theme of North Portland based venues? I figure we will keep moving each month until someplace just screams to be the new “permanent” home.

See you there!

-Mark

We had a pretty decent turnout for a warm afternoon. It helps that there was sunshine yesterday as well. There was a certain amount of confusion as to which Lucky Lab was the right one, but eventually 10 people showed up.

We played one bracket, single elimination, and one round robin tournament. It almost sort of worked. I wonder if a double elimination wouldn’t have been better, but what’s done is done. If there had been more people or 2 fewer, I think the bracket would have been a little smoother. But live and learn – best alternative.

Bryan walked away with the win in the main bracket, with newcomer Courtney taking second place. Hopefully we’ll see her and Justin again next time as well – a little bit of beginner’s luck to keep people coming back and all that. In the round robin, Paul and Martin ended up tying with 12 games each, and so split the prize there, minimal though it was.

I ended up playing Gints twice – once in the bracket and once in the round robin. At one point he took a picture of a position to evaluate later, and if he sends that along I will update this post with it. In our first match, he had sent quite a few of my checkers back, and I was starting to give up hope that I would get a return hit. But I had a relatively strong board, and eventually the opportunity did arise. A roll or two later, we got to the following position, and I offered him a double:

I’m showing it here from my side of the board – Gints is red, facing the cube. What’s the play? I’ll tell you it was a good double, and I knew it right away because he had to stop and think for a bit. Evaluation from both GnuBG and XG say it’s a double. I’m up 61 pips in the race, and likely to get a better position with my next roll. But I do have 3 men back, and no outfield coverage. As it happened, Gints took, and that is the correct action – barely (for me). XG says if my checker on 23 was on 24 instead, that this is a no double/take position. In fact, I managed to pull off my 30% gammon chance, which took us from 1-each to me winning the match. But Gints was right to take, and so that’s the important thing.

In my last game with Paul, we got to the following position, with him leading 3 to 2 in our match to 5.

In the game, I redoubled. Risky play, or sensible? Paul took – smart, or overly optimistic?

Now, here the round robin tournament rules come into the decision. Martin had 10 games, Paul and I each had 6. In order to beat Martin, it was necessary both that one of us get to 6 games (most allowed is 1 over the match length), and that Martin win at most 1 in his last match. So, although this is a proper redouble, it would normally be a pass; but Paul took it on the chance that one of us would end the match with 6 games. And so it happened – I couldn’t cover the 4-spot, and was still pulling my back checkers around when Paul came back in, hit me on the way, and went on to recover the game. Meanwhile, Gints was playing spoiler, beating Martin 6-2 in their match – putting Paul and Martin tied. Overall tournament results on player rankings are as follows:

Player	Initial Elo Rating	Matches Played	Matches Won	Final Elo Rating
Bryan	1492.7	3	3	1544.62
Mark	1556.2	5	2	1534.45
Paul	1471.7	4	3	1508.49
Julie	1516.5	1	0	1502.82
Courtney	1500.0	3	2	1500.48
Martin	1600.0	5	3	1500.00
Sara	1500.0	1	0	1482.11
Justin	1500.0	1	0	1480.66
Jarom	1488.7	1	0	1471.04
Gints	1500.0	4	1	1469.33

Overall, I believe a good time was had by all. We’ll try another location next month, when we go back to the actual second Sunday of the month on June 10th – maybe somewhere with a good happy hour. See you there!

-Mark

We had a great turnout for today’s Chouette – 9 people total. Mark F kept order on the “Advanced” board, where 5 brave souls played for $10/point; while I (mostly) played with 3 others on the “Beginner’s” board at $0.50/point. I say “mostly”, because I did get in about 4 games on the “Advanced” board, both before and after the “Beginner’s” board ran. Martin, Mark S, and Bryan were all still going when I left at 6:30, too!

The action was hot on the “Advanced” board, of course, with Martin coming out well ahead but decent showings for a few others as well. Martin and Bryan are both off to Vegas later this week for the US Open, and so we all wish them good luck.

The “Beginner’s” board was far more relaxed – couple of times people took a double that was probably a technical pass in an attempt to get the box. I had a good run as the box at the outset, which left me well up through the later rotation. Michael provided the board for the first bit, then we switched to Julie’s board when he needed to head out. Paul made his return appearance and I can assure you he hasn’t gotten rusty while he was traveling – he walked away with $0.50 in winnings!

Here’s one position we ended up arguing about for a good little while. At the “Beginner’s” table, we had full consultation at all times, including occasionally the box helping the field or vice versa… Anyway, the argument was, do you come out or do you stay on the opponent’s 4 point?

 

Julie was the captain, and wanted to come out past the bar. Paul and I were not so sure, and thought staying in provided more chance of a hit. Julie went with the escape, and good thing – staying back is a blunder! Black is not in good shape, but has 31% winning chance if he comes out, only 16% chance if he stays back.

Later, in the following position, I offered Julie the cube. Good move? Would you take?

I figured that I needed 5’s to get out, there’s a decent chance that won’t happen, and so this looks like a double/take. Julie disagreed, and dropped. Well, I was off! My winning chances are about 73% according to GnuBG, but my gammon chances are 41%, making this position too good to double! I clearly need to work on my probability estimates. Then again, with the Jacoby rule, it’s a proper double but still a drop. Lucky me, I wasn’t on the receiving side of that cube decision.

We’ll be back at Lucky Lab for a chouette next month, probably earlier in the month, as the second Sunday tournament will be moving to the third Sunday to not conflict with Mother’s Day, and then following that is Memorial Day. So yeah, the schedule will shift a bit. See you then!

-Mark