This article originally appeared in the February 2003 issue of GammOnLine.|
Thank you to Kit Woolsey for his kind permission to reproduce it here.
As in the first of this series, the positions discussed here all
arose in matches on Gamesgrid with GGraccoon. However, his comments on
why he made certain plays or how he would follow up after the various
options are only my conjectures.
It's been over a year since I interviewed the bot we all love to hate at his isolated castle in the deep, dark woods of the virtual world of Gamesgrid. Since we didn't part on what I would consider the best of terms, I was a bit surprised last June when I received a letter on his stationery asking if I'd like to do a follow-up some time. I e-mailed him back that I would, and he said this time he'd like to come visit me instead of having me return to The Lair. I recalled the difficulty of reaching his home on those primitive back roads, and readily agreed to do the interview at my farm and give him a tour of the place.
So I'm not too surprised one morning in early August to see GGraccoon turning into my gravel driveway. However, I'm a bit taken aback by how he arrives. He's driving what appears to be a small covered wagon, and is holding the reins of a large, horned, grayish-brown animal that's pulling it.
GGraccoon gives the reins a quick tug, then climbs down from his perch on the driver's seat. He's straightening the lapels of his new Italian suit and brushing dust from the road off his loafers when my neighbor's guard dogs rush toward the property border, barking and snarling. I can understand why they're excited. Though at three feet, four inches, GGraccoon's not exactly a "Giant of Backgammon", he still has to be the biggest raccoon they've ever seen.
"Stop that, Smoky! Calm down, Julie!" I admonish them.
They quiet down, and stop just short of the row of bushes separating my property from the neighbor's. I see that GGraccoon is highly impressed at my easy control of the dogs, but then I realize he doesn't understand the significance of the pink flags marking the perimeter of the electric fence. I decide not to enlighten him!
"What kind of animal is that?" I ask. "It looks kind of familiar, as if I should know but just can't place it. Is it an antelope, maybe? Or an African wildebeest?"
"Now, now," he remonstrates. "What's the first thing you learned about me and my buddies when we first came to Gamesgrid after the talks broke down in their labor dispute with the Snowies?"
"Eewww! I should have known..."
"That you and the others are powered by...a 'GNU engine'. Oh, that's awful!"
"No worse than some of the puns you've posted at the GammonLine bulletin board," he retorts. "Well, what have you got for me here? Why don't I take a quick look at one of those position cards while we start the Grand Tour?"
I hand him this one:
"You're well-known for your extremely aggressive contact bearoffs," I begin. "Usually I figure you're just trying too hard to get a gammon, but here that explanation doesn't wash since it's your Crawford game and all you had to think about was winning."
"That's all I was thinking about when I played 6/2, 3/off," he counters. "Haven't you ever seen an opponent roll back-to-back big sets and win what looked like an impossible race?"
"Hmmm..." I said, thinking of one non-human opponent in particular.
As if he could read my mind, he added, "I seem to recall you having posted something at GammonLine quite recently about someone from your real-life chouette doing just that."
"Well, even the other bots thought this move was a little extreme, and they don't always choose the safest plays either," I point out. "On their highest settings, JellyFish dinged it by .067 and Snowie by .057, though a 2-ply 512-trial rollout shows it was wrong by only about half this much, only .033. You lose 1.6 percent more games with your play than you would by just moving both spares off the 6 point."
"And that's from the two bots that first taught most of you humans to take more chances pursuing gammons," GGraccoon observes. "Here, on an equity basis, they erred on the safe side, even though they would have made the right play. Maybe when gammons aren't involved, you need to at least consider that a slightly more risky play than they recommend may be best if it bears off an extra checker."
"Sounds like good advice," I tell him.
"I might not make this same play at a score where I'd have to worry about a close cube coming my way after a hit," he speculates. "At Crawford, at least I always get to see whatever equity remains after being hit, because of the men already borne off."
Like most of the raccoons around here, GGraccoon is very interested in the apple trees.
"Would you like an apple?" I ask.
"Sure," he says, shimmying up the only tree that has any ripe fruit this early in the season.
"Irish Peach," he correctly identifies it. "Not my favorite, but the good ones all ripen later. Maybe I was thinking something like that when I didn't hit in the position on your next card."
I had been quite surprised at the time when the normally aggressive GGraccoon had declined the hit here:
"While I was watching this game, I felt sure hitting from the 12 point was right, so I asked JellyFish about it," I told him. "Even with the gammons meaning so little at the score, it strongly preferred the hit, by .103 on its Level 7 evaluation. Snowie concurred with a difference of .081 on 3-ply."
"I guess I just hated to give him an easy way to get back in the game," GGraccoon responded. "That's why I decided to leave three fewer shots here with 8/3, 12/9. He doesn't need much of a turnaround to throw the cube back at me here."
"Agreed," I said. "But one question we have to ask is whether you're more likely to see that turnaround in the long run if you don't hit now. Another is whether the hits after your play are somehow worse because he escapes a back checker at the same time, avoiding (at least for awhile) the possibility of later breaking his board with a roll like 33 or 22."
"That's a bit past my lookahead," GGraccoon grumbles.
"We humans can identify and try to quantify things that might happen farther down the road," I continue. "But when we study backgammon, we also do bot-rollouts to see the future of the game in a more precise way."
"More precise doesn't always mean more accurate," the bot retorted. "Still, I see that Snowie's 216-trial 2-ply rollouts favor the hit by .069, with the hit leading to 69.0 percent wins but my play getting only 65.9 percent. Since that's consistent with both your other bot-friends' evaluations, I guess it's good enough to hang your hat on."
"By the way, you were playing one of the best humans in the world in this match," I noted. "Did you save the file to review?"
"Are you kidding?" he asked. "I have over 10 million experience points now! If I saved all my match files, where on earth would I keep them? But even if I had a few terabytes to work with, I still wouldn't save them, since I can't learn from them the way you humans can. That is one of your great strengths, you know. I may be more consistent, but you can improve over time if you're willing to work at it."
"Speaking of which, here's one where you did take the aggressive approach, which I think of as being more your style," I said as we walked down by the creek to check out the raspberries and blackberries. I showed him the card with this position from a match with a world-famous expert and author:
"You had given him one of your infamous hair-trigger doubles at 4-away, 2-away, then passed up the bar-anchor in this position in favor of waiting back for a shot, or something," I said. "While at this score, it's less bad than at any other, these 216-trial 2-ply Snowie rollouts still show your play of 18/13 is wrong by .041 versus 22/18, 10/9."
"Of course the reason I did it was to try for those 6.1% extra gammons," he explained. "Snowie's evaluation showed only a 4.0 % gain in gammons with my play, but I felt sure it would actually be higher. And if I'd been rolling it out instead of Snowie, it might have been a still greater difference. One of the reasons would be the aggressive way I play bearoffs, as you noted in the first position you showed me today."
"Even if that's true, I'm not sure it would make your play right," I countered. "After all, the reason your bearoff plays tend to be too aggressive is that they lose too many additional games for the amount of added gammons they give you."
"Still, though, there's a case for making plays that might be technically wrong, but that better suit your style so as to avoid possibly larger errors later," he observed. "This idea shouldn't be carried to extremes, but I don't think a .041 difference is overwhelming. In this case, I'm going to stand by my play, as being the best way to win given how I'm going to follow up in both cases."
"Yes, that is something we humans need to explore in more depth, and also think about while we're playing," I agreed. "And the flip side is that we should try to make plays that draw significant errors from our real opponents, even if they'd be slightly worse versus some non-existent perfect opponent."
"I don't have to force my opponents to make errors," he said, smiling broadly. "They make plenty on their own, and some of the worst offenders are the ones who complain the loudest about my so-called 'luck', or accuse me of using rigged dice."
We walk back to the driveway, and I'm a bit upset to find the GNU snacking on the star anemones by the front lamp post. GGraccoon notices the garbage cans beside the entryway add-on, and asks what's in them.
"You wouldn't happen to have thrown out any fish sticks or fried chicken?" he asks hopefully.
"Get away from there!" I shout. "And tell your relatives down by the creek the same! They better stay in the woods where they belong, or I'm going to take up fur trapping!"
"Easy!" he admonishes. "I may wear Gucci for Rodents, and live in a mansion with servants and a hot tub, but every so often I revert to my baser instincts. Money doesn't seem to cure this tendency, any more than it does for you humans."
"No kidding," I respond. "But just the same, stay out of those cans, and don't bother ripping up the empty pizza boxes either. I haven't a clue why you raccoons always do that!"
"Hope, I guess," he says. "The same kind of feeling that keeps you coming back to this game, hoping for that big payday, either in rating points or perhaps something a little less virtual."
"Indeed," I agree as he climbs back onto the platform that serves as the driver's seat for his carriage. "See you on Gamesgrid!"