Thursday, April 25, 2013

Cribbage Strategy - Timing Your Opponent


Up until now this blog has focused on how to play your cards, but there’s another important part of cribbage strategy: playing your opponent. Let’s see what you can tell about your opponent’s hand from the amount of time it takes them to play.

How good is your opponent’s hand?

Did your opponent discard quickly, or did they take several seconds to choose their discard? That timing turns out to be a great indicator of the strength of their hand. When your opponent discards in just a second or two she (on average) has a stronger hand than she does when she takes 15 seconds or more:

Cribbage Strategy - Timing Your Opponent

Our data shows that when dealers take only a second or two to discard they've scored around 16.5 points during the hand (between pegging, counting her hand, and counting her crib). When dealers have taken more than 15 seconds to decide they've scored, on average, around 15.2 points

Dealers that take a long time are also much less likely to end up with a big game-changing hand. We've seen that dealers scored 20 or more points in 27% of the hands where they've made their decision in 2 seconds or less, but only in 20% of the hands where it took them more than 15 seconds to decide.

The difference is even more dramatic for pone. We've seen that pone averaged 11.4 points (between pegging and counting her hand) on the hands when her discard decision was made in one or two seconds, but only 9.5 points when pone took longer than 15 seconds. And pone scores 20 or more points in 5% of the hands that were decided in one or two seconds, but only 2% of hands that took longer than 15 seconds.

You can use this information when deciding whether to play offense or defense. Instead of using our dealer/pone averages of 16 and 10, you can estimate your opponent’s end-of-hand position based on the the above table and her discard time.

“Should you pair your opponent’s lead” revisited

When pone discards quickly she’s more likely to keep a pair, and therefore more likely to lead from a pair. Be extra cautious about pairing your opponent’s lead when she discarded quickly. In an earlier blog post we suggested that you should only pair a great player’s lead if she leads with a 3, 4, or 8. Our data shows that pairing pone’s lead is even more dangerous when she discarded quickly -- in that case the 4 is the only lead card you can pair without giving up more points than you gain on average.

The chart and table below have the details. They show the probability that pone is setting you up for a trap with her lead card (that is, that pone would score three of a kind for 6 points if you paired her lead card), broken down by the amount of time it took pone to discard, and pone’s lead card. (Note that the numbers aren't the same as in our earlier blog post. Since then we've added a few million additional hands of data to our sample, and the statistics have shifted a little).

Probability pone’s lead is a trap (when lead is different rank than cut)

Cribbage Strategy - Percent of Hands that are a Trap

Lead card
Overall
If pone discarded slowly
If pone discarded quickly
A
49.68%
45.54%
54.52%
2
39.46%
36.80%
48.51%
3
27.30%
25.02%
37.19%
4
23.79%
20.74%
34.15%
5
43.42%
40.92%
54.55%
6
36.22%
29.67%
51.92%
7
31.95%
27.58%
46.16%
8
28.54%
24.73%
36.11%
9
34.58%
27.73%
58.45%
10
35.18%
28.29%
51.65%
J
35.84%
28.59%
50.82%
Q
32.42%
27.79%
41.86%
K
32.44%
28.38%
37.25%


Next topic: a question from Craig

Cribbage Pro player Craig sent an email asking what pairs were most likely to show up in pone’s hand, and what were most likely to show up in dealer’s hand. The results are interesting: pone is more likely to keep a pair in her hand, and significantly more likely to keep a pair of cards 5 or higher. About 6% of pone hands include a pair of fives, vs. only 5.2% of dealer hands.

Also interesting is that fact that most hands include a pair. In fact, around 60% of pone hands include at least one pair.

Here are the gory details for the mathematically inclined:
Cribbage Strategy - Percent of Hands with a Pair


Pair
% Dealer Hands
% Pone Hands
A
4.2%
4.3%
2
4.3%
4.4%
3
4.6%
4.9%
4
4.9%
5.1%
5
5.2%
6.0%
6
4.8%
5.2%
7
4.4%
5.1%
8
4.3%
4.9%
9
4.5%
4.9%
10
4.6%
5.0%
J
4.6%
5.0%
Q
4.3%
4.6%
K
4.0%
4.4%


More questions?

We love answering these types of questions. Do you have another one for us? Just leave a comment and we’ll see about answering it.


Editor's Note: This is a guest post by Aaron Harsh continuing the series on cribbage strategy and tips. Aaron lives in Portland, Oregon with his wife Stacy and daughter Audrey. He spends his evenings analyzing cribbage strategy for Fuller Systems, and his days analyzing television viewership for Rentrak Corporation's Advanced Media & Information group. You can play him on Cribbage Pro Online as user "aaronhars", or in person at American Cribbage Congress grassroots club #28 (Oregon's Finest).

6 comments:

  1. I know this has nothing to do with the game. Instead of having a button that say "kick player" how about saying something like "pass on player" or "decline" or "no thanks" just a suggestion. Kick seems a bit harsh. What do you think?

    ReplyDelete
    Replies
    1. Thanks for the suggestion. The term used today was based on research of similar online multiplayer games, so we stuck with what was a kind of de facto standard. I'll pass this along the team and see if the market has shifted from this and if we should too. I agree it is can bee seen as a bit "harsh".

      Delete
  2. If I discard slowly it means I changed the TV channel, ate a handful of popcorn, or similar before I acted. I really hope this post doesn't slow players down.

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    Replies
    1. Funny, but definitely true for some players. It all depends on how and why you play. I'm sure some will try and be "tricky" and switch up their "tell" like people try and do in poker games, but still others may be pressured to play faster in other situations. Ultimately, you won't know which is which, but the averages will probably still play out as it is like any other thing people do out of habit, and changing is hard.

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  3. Great stuff! Thanks for answering my question, Aaron!

    ReplyDelete
  4. Interesting that the Pone is MUCH more likely to have a pair of 7s than the Dealer. I guess middle cards are popular choices for the Dealer to discard....

    ReplyDelete