Spikes

From Simplex

Contents 1 Motivation: Simplicity 2 The Valuation 3 Naming 4 Notation 5 Findings 5.1 Stoppers 5.2 Likely Tricks in a Suit 6 Examples 6.1 T101#12

Motivation: Simplicity

It has long bugged me that bridge players are expected to learn many different forms of hand evaluation, e.g.

• HCP (e.g. to determine which level to raise partner to), losers (e.g. to decide whether to overcall 1NT),
• suit length (e.g. to determine the best trump suit),
• stoppers (e.g. to investigate the possibility of a 3NT contract),
• Rule of 19 etc totals of HCP + length of two longest suits (to test compliance with the EBU Orange Book),
• Suit Quality Test (e.g. to evaluate the possibility of an overcall), and
• counts of aces and kings (e.g. to assess the possibility of slam).

It would be very helpful to beginnners and others if this list could be reduced, even if it means introducing a new valuation method. It would also be helpful if a single numerical valuation could describe the hand, accounting for both high-card strength and suit length, in particular.

The Valuation

We devised the simplest possible measure which takes into account both strength and suit length: HCP + suit length. This basis, or variations thereof, must have used countless times before. Fr example, Klinger proposes that, until a suit fit is found, bidders should value a hand by adding length points to HCP, where a length point is each card beyond four in a suit.

Naming

The last thing the bridge community is another meaning to the word 'points'. It is already confusing enough for beginners that points are used both for scoring and hand evaluation. The most appropriate monosyllabic synonym I could find was 'spike'. So

Spikes = HCP + suit length

So the spike count of your hand is just 13 more than your HCP. No insight there. The real insight comes from looking at the distribution of spikes across all four hands within each suit. As there are 10 HCP and 13 cards in a suit, there are 23 spikes in each suit across the four hands.

Notation

An important decision is how to portray the distribution of spikes in anyone suit across the four hands. As anyone who has typeset a maths text knows, it is relatively very time-consuming to depict any expression which could simply be typed linearly from a typewriter. So a compass depiction of N, S, E and W would cumulatively add much cost to the spike distribution analysis. A simple vector expression — e.g. (4, 3, 9, 7) — does not indicate the back-to-the beginning rotation. Instead we use superscripts and subscripts to give some indication of a diagonally squashed and rotated bridge table:

_W^N_S^E ♥(₆¹⁰₃⁷)

Note the use of rounded brackets and the ordering (W, N, E, S) as per the standard bidding record. As we become familiar with the notation, the W N E S prefix can be omitted for brevity.

Findings

Stoppers

Any suit holding of 5+ spikes — A or K-x or Q-x-x or J-x-x-x or x-x-x-x-x — constitutes a stopper, either likely or certain.

Likely Tricks in a Suit

Likely Partnership Tricks in a Suit
Total Spikes in Suit held by Partnership	Spikes in Suit in One Hand	Spikes in Suit in Partner's Hand	Likely Tricks
18	17	1	7
18	16	2	5 (T101#12)
16	15	1	4 (T101#12)
15	14	1	?
14	13	1	?
13	12	1	?
12	11	1	?

Examples

T101#12

The configuration is: