What Card Should I Lead? Lightning Round Edition

One of the great things about our huge database of cribbage games is that we can identify hands that are frequently misplayed. Today we're going to give a high level overview of a few of those hands. Keep in mind that these results aren't our opinions -- they're the actual results across a sample of millions of cribbage hands. Some of these results are just as surprising to us as they are to you.

A-4-X-X

About 4.8% of pone (non-dealer) hands will hold an ace, a 4, and two 10s/face cards. (From now on we'll use "X" as a shorthand for "a 10 or a face card"). Most players lead the 4 from this hand, but around 7% lead the ace. The players that lead the ace, on average, have a 0.55 point pegging advantage: they peg 0.18 points more, and their opponents peg 0.37 points fewer.

Why is the ace a better lead? There are pros and cons to either lead, but our data shows that by far the biggest factor is that dealers are less likely to pair an initial ace. Of the tens of thousands of A-4-X-X hands that we've analyzed we've seen that the dealer pairs a lead 4 at 19.93% of the time, but only pairs a lead ace 12.84% of the time. An interesting and common case is when both players have A-4-X-X hands. Here's how the pegging plays out in that scenario when dealer is willing to pair a 4 but not an ace:

Pone leads a 4

Pone	Dealer	Points
4
	4	+2 for dealer (pair for 2)
X
	X
A
	A	+3 for dealer (pair for 2 and a go)
—
X
	X	+1 for dealer (go)

Pone leads an Ace

Pone	Dealer	Points
A
	X
4		+2 for pone (15 for 2)
	4	+2 for dealer (pair for 2)
X
	A	+1 for dealer (go)
—
X
	X	+1 for dealer (go)

Leading the 4 gives dealer 6 points to pone's 0 for a net disadvantage of 6. Leading the ace gives dealer 5 points to pone's 1 for a net disadvantage of 4. Executive summary: lead the ace from A-4-X-X.

A-7-8-9

Most players lead the 8, but leading the ace gives a 0.78 point advantage (pone pegs 0.38 points more, and dealer pegs 0.40 points fewer). The data shows dealers making a couple mistakes when pone leads the ace:

• Dealers holding 5-X-X-X see the ace and expect pone to have a 4. Dealer plays her 5 to avoid giving pone a a 15-2. Pone plays a 9 on dealer's 5 and pegs 15 for 2 points.
• Dealers holding middle cards (6s through 9s) end up trading runs back and forth with pone, and usually lose in this situation

Executive summary: lead the ace.

A-A-5-9, and A-6-8-9

At the risk of seeming predictable, we're going to suggest leading the ace for these two hands. A-A-5-9 is one of the few hands that most players are playing properly: 50.3% of Cribbage Pro players lead the ace from this hand.

Leading the ace from A-A-5-9 averages a 0.50 point advantage over leading the 9. Leading the ace from A-6-8-9 averages a 0.57 point advantage over the 8 (the most popular lead, and the second best choice).

Executive summary: lead the ace.

5-5-6-7

The last hand we'll look at today is 5-5-6-7. Most players correctly lead the 7, but about a third lead the 6. Leading the 7 gives a 0.57 point advantage over the 6.

The big story here is that pone comes out better if dealer plays an 8 on pone's 7 than if dealer plays a 9 on pone's 6. When dealer plays an 8 on pone's 7, dealer averages 7.59 points of pegging to pone's 3.68 (for a net -3.91 loss for pone). When dealer plays a 9 on pone's six, dealer averages 5.99 pegs to pone's 0.88 (net -5.11 point loss for pone).

That's it for today

Disagree with these results? Want to see the results for another hand? Leave us a comment below and we'll get back to you.

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).

What card should I lead? (Part 2)

Today's topic is on playing 4-5-6-6 as pone. This is going to be short and sweet, because the wrong way to play this is just so wrong! This is one of the first hands cribbage players study when they begin to take the game seriously, and playing it correctly is a great way to start improving your game.

Lead the 6 and trap the dealer's 5

It would be foolhardy to lead the 5, and the data shows that Cribbage Pro players rarely do that. But 32% of players are leading the 4 from this hand, and that's just plain wrong. Here's why (keeping in mind that the two most common hands for dealer to have are 5-10-J-Q and 5-J-Q-K):

Pone	Dealer	Points
6
	K
6
	5
4		+5 for pone (run for 3 and 31 for 2)
—
	Q
5		+2 for pone (15 for 2)
	J	+1 for dealer (go)

This play is commonly referred to as the "non-dealer 5 trap." The dealer is trapped after pone plays her second 6: the count is 22, and the 5 is the only card she can play without taking the count over 31. Pone ends up pegging 7 points to dealer's 1, leaving pone with a net 6 point advantage.

That's awesome! Let's talk about it some more!

One of the great things about this play is that the dealer has no escape route: he can't play his 5 on pone's initial 6 (he'd be out-pegged 9 to 1 if he did), so he has no hope but to sit back and watch pone peg away. Personally, my heart sinks a little when I've got 5-J-Q-K and pone leads a six.

Another great thing about this play is that it works fairly often. Pone scores her 7 points as long as dealer's hand is made up entirely of 10/face cards and 5s. Dealer has one of those hands about 9% of the time, which is pretty often in cribbage terms.

You can peg almost as many points without the 5. Any hand with a 4 and two 6s in it is a candidate for this five trap. You won't score that last 15 for 2, but you'll still get the run for 3 and the 31 for 2.

In a defensive situation? Lead the 6

Surprisingly the 6 is a better defensive lead than the 4. On average the dealer pegs 3.90 when pone leads the 6, vs. 4.05 when pone leads the 4. (These averages are based on several thousand 4-5-6-6 hands played on Cribbage Pro Online).

Even better, when pone leads the 6 dealer is limited to just one point 22% of the time, vs. 9% of the time when pone leads a 4. Here's a chart that shows the dealer pegging probabilities for the two leads:

There's a 22% chance that the 6 lead will hold the dealer to 1 point of pegging, but only a 9% chance that the 4 lead will do that. The 4 lead's only advantage is that it's slightly more likely to keep dealer's pegging under 8 points (8.82% chance of dealer pegging 8+ points if you lead the 4, vs. a 9.15% chance if you lead the 6).

Executive summary: there's no defensive advantage to leading the four.

Desperately need to peg a point? Lead the 6

Here's a similar chart, showing pone pegging probabilities.  Note that we swapped the “=”s out for “=”s in this chart -- the “=1” bar in this chart shows the chances that we’ll score at least one point, rather than at most one point.

The 6 lead wins across the board: you're more likely to peg at least one point when you lead the 6 (67% chance, vs. 56% when you lead the 4), and more likely to score at least two points (52% for the 6 vs. 40% for the 4). In fact, no matter how many points you need to peg, you're more likely to get those points if you lead the 6.

Executive summary: there's no offensive advantage to leading the four.

Moral of the story

The 6 lead is superior in ability to score a small number of points, ability to score a large number of points, and ability to keep dealer from pegging. You should always lead the 6.

Is there ever a situation where the 4 is the right lead? Leave us a comment and let us know what you think.

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).

What card should I lead? (Part 1)

We talked about some basic dealer pegging strategy in our last post. Let's switch it up a little and talk about pone (non-dealer) pegging strategy. The first pegging question for pone is "What card should I lead?" As usual, the answer depends on your objective at the moment (Score at any cost? Keep your opponent from scoring? Go for most net points pegged?). We’ll focus first on optimizing net points pegged.

For our analysis we'll measure net gain for pone as the average (mean) number of points pegged by pone minus the average number of points pegged by the dealer. So if pone pegs 5 and dealer pegs 3 the pone has a net gain of 2, and if pone pegs 10 and dealer pegs 12 the pone has a net gain of -2 (or a net loss of 2).

If there's enough interest we can examine other metrics in a future post (e.g., probability of pone pegging at least one point; probability of keeping dealer's pegging below some threshold).

6-7-8-9

Our data shows that pone keeps 6-7-8-9 in his hand around 0.7% of the time. That doesn't sound like much, but that actually makes it the third most common hand (after 5-J-Q-K and 5-10-J-Q), so it's worth spending some time analyzing this hand.

6-7-8-9 is the hand that got me interested in analyzing this data. It seems like whenever I play the 8 my opponent plays a 7 on top for "15 two"; and when I play my "9 for a run of three" she's got a "6 for a run of four." Is 8 really the right lead? And if it is, is "9 for run of three" really the right play when the dealer plays "7 for 15 two"? Or should I play "7 for a pair" instead?

John E. Chambers (in Cribbage, A New Concept) suggests that we lead the 6 from this hand. Let's stir up some controversy by respectfully disagreeing with Mr. Chambers!

Lead the 8

There's an ugly truth here that needs to be accepted: the dealer is probably going to outscore us. This doesn't mean that 6-7-8-9 is a bad hand, just that dealer has the advantage when pegging. The best we can hope to do is to keep the gap between dealer's pegging and ours as close as possible.  Cribbage Pro players have played this hand tens of thousands times, and on average they see these results:

Pone lead	Avg pone points pegged	Avg dealer points pegged	Avg pone net points
6	1.84	3.52	-1.69
7	1.93	3.68	-1.76
8	2.07	3.53	-1.46
9	1.87	3.63	-1.75

Leading the 8, on average, gives us a net advantage of 0.23 over the 6 lead (which, to be fair to Mr. Chambers, is the second best lead). The 6 limits dealer’s pegging almost as well, but doesn’t peg as well for pone.

Why does pone score more with the 8 lead? The detailed explanation why is very, well, detailed. If you're interested leave us a comment, and we'll show the gruesome details, with probabilities and results for every possible response to your 8 or 6.

What next?

What should you do when the dealer inevitably plays a 7 on your 8 lead? The answer is (drum roll)... play the 9. Your opponent will have the "6 for a run of four" 42% of the time, but 58% of the time she won't and that's enough to make the 9 the right choice. Average net gain for pone is -2.11 playing the 9 on top of the dealer's 8, -2.80 playing the 6 on the dealer's 8, and -3.17 playing the 7.

Defensive situations: maybe the 6, maybe the 8

Sometimes it’s more important to keep your opponent from scoring than it is for you to score. If your opponent is four points away from pegging out, for instance, you want to maximize the odds that she scores 3 points or fewer. The chart below show probabilities of limiting dealer to any number of points pegged.  It’s interesting to see that the 8 lead is more likely to limit your opponent’s pegging to 5 points or fewer, but the 6 lead increases the chance that your opponent pegs 12 or fewer.

Hail Mary pegging: lead the 8

If you desperately need 10 points to go out, you’re going to need to peg an extra 2 points on top of the eight points already in your hand. The 8 is almost always the best offensive pegging lead. The only exceptions are if you need to peg at least one point (lead the 6), or if you need to peg eight or more points (lead the 7).  The 7 is also your best choice if you need to peg more than ten points -- we've seen pone peg 11 about one time in a thousand when she leads the 7, but we've never seen pone peg 11 with an 8 or 9 lead. The chart below shows the details:

Executive summary

Moral of the story: you should almost always lead the 8 from 6-7-8-9, and feel confident playing that 9 for a run of three. You're probably in for a painful pegging experience, but you're going to get out-pegged no matter what you do.

We'll talk more about pone pegging strategy in the next post. Do you have a hand you're especially interested in? Leave a comment and let us know.

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).