Index of Analysis Projects

This page is an index to projects which analyse bridge data.

Tournament Travel Distances

Histogram with a clip art car and clip art airplane takeoff superimposted

How far do players travel to NABCs and regionals? Does travel behavior vary significantly from district to district? Can tournaments be classified into types based solely on the shape of their travel histograms? See the results for all the 2015 NABCs and regionals.

Tournament Table Counts

scatter plot of average number of regional vs. sectional sessions per player in 2015 by district

The ACBL held 1266 tournaments in 2015. How does this breakdown in terms of NABCs, regionals, sectionals, and STaCs? What is the table count of a typical regional or sectional? To what extent does district participation in tournament play vary in terms of average number of sessions per player in a year? Is it correlated with club participation? Does the tournament schedule affect participation? See the results.

Club Table Counts

king of clubs silhouetted by club card symbol with jagged red arrow superimposed and a space like grid in the lower half of the image

The ACBL has just over 3000 clubs. How many tables does a typical club have in a year? What is the distribution of club table counts? Which ACBL districts has the highest number of club sessions per member? To what extent do the biggest clubs dominate the total club table count? Do big clubs significantly raise a districts average number of club sessions per player? See the results.

Field Protection, Diversity, and Shannon Entropy

Shannon entropy equation superimposed on black and white fractal like artwork

Is field protection a meaningful concept? Does a stronger field provide greater field protection? How many unique results are there on a typical board in a big field? How large does a pair game have to be to avoid undersampling? Take a mathematical journey and find out.

Evening Club Bridge Is Dying

Downward red arrow superimposed on a picture of the night sky

The prognosis for evening bridge is grim. Though total club table count has remained nearly constant for the past 25 years, the percentage of those tables played in the evening has fallen from 44% to 16% over the same time period. Utter annihilation of the evening game looks certain within 15 years but collapse due to low table counts will probably occur within half this projected timeframe. See the data and plots.

Partial, Game, Slam, and Grand Slam Breakdown

Pie chart of part score, game, slam, and grand slam double dummy breakdown

What is the double dummy breakdown of part score, game, slam, and grand slam contracts? What do real bridge players bid? How does their bidding change as they become stronger players? Do players at regionals behave differently from clubs players? See the results.

The Silence of the Lambs

lamb with 3-3 suit split designation in center

A 3-3 split is nominally a 35.53% chance. But actual bridge hands include information from the auction. Since it is easier to compete with good shape, opponents who do not compete will on average have flatter hands. How much does the probability of a 3-3 split in a side suit increase when the opponents are quiet? See the results for some common auctions.

Balancing Statistics After One of a Suit

Balancing after one of a suit

How many HCP is your side likely to have when you are in the balancing (pass out) seat after the auction has gone 1♣/1/1/1♠ – Pass – Pass to you? How does it change depending on how many points you hold? How many HCPs are opener, responder, and your partner likely to hold? What is the range of the range of possibilities? See the simulation results.

Seventy Percent Session Hoopla

70% game celebration

Shake a stick in the bridge world and you’ll probably hit a list of partnerships who had a 70% or better session in the last month. How hard is it to have a 70% or better session? How much harder does it get in stronger fields? How much easier is it for strong partnerships to break the 70% barrier? Read more.

Esplanade and Eastlake Payoff Matrices

2012-2013 payoff matrix

The Payoff Matrix was introduced last October and results were presented for the La Jolla unit game and San Diego unit game. Now matrices for the Esplanade Club games and the Eastlake Bridge Club games are available for every session using data from the entire 2013 calendar year. Take an in-depth look at what is happening across San Diego.

First 1000 masterpoints revisited (2013 data)

Three people climb ladders towards a trophy

Three years ago, and again for 2012, I examined how many masterpoints players gain on average in a year based on how many masterpoints they have at the start of the year. The 2013 data set is the first truly clean dataset and it closely matches the 2012 results. See the 2013 results.

Slam Statistics

Three dancing penguins, arm to arm

Slams are not rare. Double dummy, an amazing 13.6% of hands contain a slam (or grand slam). That’s an average of 1.84 slams for your side in a 27 board session. Is your partnership bidding and making enough slams? How well do strong partnerships bid slams and what types do they bid? Read more.

Partnership Variability

Part of a roulette wheel with ball in number 7 slot

How much variability does the field create in matchpoints? How variable is the performance of a typical regular partnership? What is the range of variability? Are stronger partnerships less variable? Is some degree of variability good for the game? Read more.

The Payoff Matrix

2012-2013 payoff matrix

Which regular partnership is the strongest partnership in the La Jolla unit game? How statistically confident can we be about any determination?

Which partnerships payoff to other partnerships? Which partnerships over/under-perform against other partnerships after the disparity in skill is factored in? What has changed over the last six years? Read more.

Results for the San Diego unit game and the two games combined for 2012-2013 were added in January 2014. Read more.

First 1000 masterpoints revisited (2012 data)

Three people climb ladders towards a trophy

Two years ago I examined how many masterpoints players gain on average in a year based on how many masterpoints they have at the start of the year. The most interesting result was a steeping of the curve starting at roughly 1000 MP, suggestive of a qualitative difference between players above and below this cutoff. Since then there have been changes to the masterpoint allocation, notably a curtailment of the triple point charity games. See the 2012 results.

The Social Network

social network depicted by red and blue people connected by dotted line

Who plays with whom? How often? How well do they do on average? What percent does your partnership need to average to be in the top 10% in a game? Who is promiscuous? For an in depth look at our social network, read more.

Where are the bridge players in the Patchwork Nation?

Patchwork Nation

In 2010, journalist Dante Chinni and statistician James Gimpel published Our Patchwork Nation. Seeking to move beyond the simplistic blue and red states paradigm, they examined the nation’s 3,141 counties in terms of race, education, income, religion, and politics to get a flavor of local perspectives. They identified 12 different community types based on “common experiences and shared realities” which they breezily named boomtowns, campus and careers, emptying nests, Evangelical epicenters, immigration nation, industrial metropolis, military bastions, minority central, monied burbs, Mormon outposts, service-worker centers, and tractor country. How well is bridge doing in each community? Read more.

Three people climb ladders towards a trophy

The first 1000 masterpoints are the hardest

It is no surprise that on average the more masterpoints you have, the more you gain per year. But what do the actual numbers look like and is there more to the story? Read more.