sevens rule tweaks

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Fix the sevens rule

I got email from q that I'll edit into this ticket (after lunch), but I'm making this issue now so I don't forget.

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Ugh. I'm going to have to go back and see if I still have the correspondence. I think I do. IIRC, there was some uncertainty about certain corner cases and my, admittedly vague, recollection is that q himself didn't have a definitive answer.

FWIW, I don't think there's a bug in the current implementation, in that I believe it does what I thought the rule should be in the corner cases I've contemplated. The big one, I believe, is what to do if player A checks his 7, player B calls with a worse hand and player C raises with the exact same hand player A has and then player A calls.

In general, this is pretty low priority. OTOH, I really would like to close all issues that truly bugs.

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From q:

(If you want to discuss any of this let me know. Otherwise let me know when you have implemented it and when and where I should look. I have not mentioned "completing a bet" -- bringing an all-in player's less than a full bet up to a full bet -- because if you haven't implemented that you shouldn't and if you have you should consider taking it out. The response to an all-in less than a full bet should be that the bet can only be called or raised. Many cardrooms during California's lowball days did not have a "complete the bet" option so it would be best for you not to have it either.)

Players are likely to inadvertently pass 7s (or better) in two situations:

1. A new player gets flustered and forgets the rule. He passes without thinking. Sometimes he remembers the rule before the next player has acted, and tries to un-pass, with some such remark as, “I forget about that sevens rule. Can I make a bet now?” Sometimes he remembers after the next player has acted, often after the next player has already passed, and now when he tries to bet, an argument ensues. No matter how it happens, however, he gives away his hand, and chills the after-the-draw action.

2. A player draws several cards, usually three or more, and passes without looking at her cards, unconsciously concluding that she could not possibly make a 7 or better drawing that many cards. Of course, the time she passes blind is often the time she makes that miracle draw. What often happens is that she ends up losing money, because someone would have called a bet.

There are two obvious countermeasures for these situations.

1. The first is always be aware of the sevens rule. Remember that it is in force in almost every California cardroom that has lowball. Be aware of what your hand is when it is your turn to act, and don’t pass if you have a 7 or better.

2. The second is, when you take multiple cards, don’t pass blind; don’t assume that you can’t possibly make a hand. Look at your cards and, again, if you have a 7 (or better) after the draw and you’re first to bet, do so.

The sevens rule can come into effect when you are faced with calling an all-in bet that is less than a full bet and there are players remaining who have more chips. You can inadvertently run afoul of the sevens rule in the following way. If someone makes a bet in turn that is less than a full bet, and you just call (rather than raise) with a 7 or better, and someone calls or raises behind you, that person gets his bet back (unless he has you beat, of course).

Example: The limit is $20. Three players call, so the pot now contains $60. (For simplicity, let’s assume that all three players are the blinds.) After the draw, John, directly to the left of the button, has only $15 left, which he bets. You, on the big blind, who drew two cards, got lucky and made a wheel. You don’t want to scare the remaining player, so you just call, knowing that you can’t win any more from John. Cindy, on the button, says, “I raise,” and puts in $35. The bet skips John, who is out of chips. You say, “I raise,” and someone at the table informs you that since check-raising is not permitted in limit poker, all you can do is call. A side pot of $40 is created and there is a showdown.

John made 8 4 3 2 A, and is out of contention. You show your wheel 5 4 3 2 A ­ and start to reach for the pot. Cindy shows 6 4 3 2 A. The house dealer pushes Cindy’s post-draw betting ($20) back to her and $20 back to you (returning your “illegal” bets) and pushes the center pot to you ($125, consisting of that initial $80, plus the $45 that constitutes the $15 that John bet and you and Cindy called; since you broke no rules before the draw you’re entitled to what was in the pot before the draw.) Had you initially raised, you would have won a lot more. Cindy has the second-best possible hand and would surely have reraised, and she probably would have put in several more bets.

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Hmmm... I don't think the above actually helps me with the corner case of a violator and non-violator of the sevens rule tying for best hand. I'll need to dig further into my email to see if we ever discussed that. I can't find any such correspondence, but I have a memory that we did discuss it.

In the meantime, I'm removing the bug label.