Pearson Points: the Rule of 15 for Fourth Seat Openings

Pearson points decide whether to open in fourth seat after three passes. Add your high card points to the number of spades you hold: with 15 or more, open the bidding; with 14 or fewer, pass and let the deal be thrown in.

This test is also called the Rule of 15. It is named after Don Pearson. It belongs to no single system: Standard American, 2/1 and Acol players use it the same way.

1. Count your high card points.
2. Add one point for each spade.
3. Open with 15 or more. Pass with 14 or less.

The second hand opens 1♣ because with 3-3 in the minors that is the standard choice; it shows no extra values.

In fourth seat you are not deciding whether your hand is an opening bid. You are deciding whether you want to play the deal at all. Passing it out scores zero for both sides. Opening starts an auction that the other three players join with full knowledge that everyone has a modest hand.

Three passes tell you something useful: the high cards are split fairly evenly. If you hold 11 or 12, the other 28 or 29 points are spread over three hands that all passed. The deal will be a fight for the partscore, and in a partscore fight the side with spades has the edge. Spades outrank every other suit, so the spade side can compete at the same level while the other side has to go one higher.

Short spades are a warning. They usually mean the opponents hold the spades, and opening will help them find their fit. Long spades mean you can keep outbidding them.

South has a normal 12-count and would open 1♥ in first seat. In fourth seat it has 12 + 1 = 13 Pearson points, so the rule says pass.

See what happens if South opens anyway. West overcalls 1♠ on a five-card suit, East raises, and the spade partscore beats the hearts. Double dummy, East-West take nine tricks in spades while North-South take only eight in hearts. North-South cannot outbid spades at the same level, so opening turns a zero into a minus score.

The Rule of 15 is for one situation: fourth seat, after three passes, with a hand in the 10 to 14 point range. Outside that window you do not need it.

• 15 or more HCP: open. You pass the test with no spades at all.
• Fewer than 10 HCP: pass almost always. Even with five spades, a 9-count leaves the opponents with most of the deck.
• First and second seat: use the Rule of 20 or your normal standards.
• Third seat: partner has passed, but your LHO has not, so light openings for the lead are fine there.

Preempts work differently in fourth seat. There is no one left to preempt, so a weak hand simply passes. A two-level or three-level opening in fourth seat shows a sound hand that wants to play there, often a good six-card suit with 11 to 14 points.

A total of exactly 15 or 14 is where judgment comes in. Look at these points before you decide:

• Suit quality. ♠KQJ94 with 10 HCP elsewhere is a happier opening than ♠97542.
• Hearts. Long hearts are second best. With 14 Pearson points and six good hearts you can open, because hearts outrank both minors.
• The form of scoring. At matchpoints, passing out gives you an average on the board, and a thin opening risks a bad score. At IMPs, a partscore swing is worth only a few IMPs either way.
• Vulnerability. If you are vulnerable, minus 200 hurts more. Lean toward passing.
• Defense. Aces and kings help if the opponents buy the contract. A hand of queens and jacks does not.

Compare two 15-point hands: ♠AQ1073 ♥K62 ♦84 ♣J63 (10 HCP + 5) and ♠J7 ♥QJ5 ♦KQJ4 ♣K1052 (13 HCP + 2). The first has the suit and the defense. The second may pass the count, but every opponent's spade bid will be a step ahead of you.

The two rules answer different questions, so a hand can pass one and fail the other.

The first hand has great shape for offense, but in fourth seat the opponents own the spades. The second is flat, but its four spades make it a fair fourth-seat opening.

Partner is a passed hand, so the auction is usually quick:

• A new suit by partner is not forcing. You may pass with a light opening and a fit.
• Partner's jump to 2NT shows about 11 to 12 points. Accept only with a full opening hand.
• Many pairs play Drury or reverse Drury, where 2♣ by the passed hand shows a fit for your major with invitational values. When you opened light, reverse Drury, the common version today, lets you sign off in two of your major; original Drury shows the light hand with an artificial 2♦.

The key is honesty about your values. Your fourth-seat 1♠ may be a Pearson-point 11-count. Make every later bid as if you hold a minimum, unless you really hold more.

• Counting hearts too. Only spades are added. The rule is about outranking the opponents.
• Using it in third seat. Third seat has its own logic: open light for the lead.
• Opening a weak two in fourth seat. A weak hand has nothing to preempt. Pass.
• Bidding on after a light opening. If you opened an 11-count, do not invite game when partner has passed and shown a limited hand.
• Ignoring the score. A 15-total at unfavorable vulnerability in a strong matchpoint field may still be a pass.

For more decisions like these with a real score, try the bidding puzzles: you are South, you choose one call, and every option is played out double dummy on many deals that fit the auction. Then read hand evaluation for the full picture of hand values, and Bergen points for another way to adjust your count.