Wracking my brain for something semi-interesting to post this week—anything really—I decided to model the baseball metaphor of sexual intimacy using a Markovian random walk algorithm. Since all I do is work these days [whine], work-related subject matter is all I’ve got to write about (Markov models being work-related, not sexual intimacy).
According to Wikipedia (http://en.wikipedia.org/wiki/Baseball_metaphors_for_sex) what follows are broadly accepted descriptions of each metaphorical base:
First base:…………………………………………………….mouth-to-mouth kissing
Second base:…………………………………………………groping underneath shirt
Third base:……………………………………………………mutual masturbation
Home (after rounding the bases):…………………….sexual intercourse
The Model. Dude has a 50/50 chance of making it to the next base on any given “play”. If he succeeds, he either continues to next base in the sequence—where he must then make another play—or he “scores” if his successful play is from 3rd. If a play toward any of the bases fails, he’s out, meaning: he must “bat” again with some new chick and attempt to round the bases starting from scratch. The matrix below captures this scenario in its entirety. It operates on dude’s current state-vector (representing the base he “occupies”) to determine his probability of making the next base in the sequence.
Transition probability matrix (“LayMatrix” in routine below):
Results. Based on this model, the half-successful dude should expect to make exactly TWENTY-NINE total plays to score. In the course of these 29 plays, he fails or “outs” with an average of 15 girls on the way to scoring with one.
Discussion. You’re probably saying to yourself: “Thug, was high school prom the last time you “scored”? Chance probability of success for each play is not realistic.” For those of us single in our third-decade-of-life-and-then-some, a more realistic progression matrix might be:

For this model (LayMatrix2), dude need only commit an expected 19-20 plays to attain score-status; though he should expect to fail with a chance-comparable 14 girls in the process. In this scenario, most failures occur trying to reach first base.
Comparing outcomes predicted by the two models, dude should score with fewer plays than chance under the “more realistic” model but will strike out with almost the same number of chicks. These models assume chicks’ acceptances of dudes’ advances obey Markovian point-process statistics (i.e. chick will accept or reject a dude’s play independent of his record of previous plays). My limited experience agrees. How else could so many ass-douches strut around with such fine wool.
Covering my ass. For those in doubt:
z0 = [1, 0, 0, 0, 0]’; % Initial state vector: at bat at home plate
LayMatrix = [0.5, 0.5, 0, 0, 0; 0.5, 0, 0.5, 0, 0; 0.5, 0, 0, 0.5, 0; 0.5, 0, 0, 0, 0.5; 0, 0, 0, 0, 1];
LayMatrix2 = [0.8, 0.2, 0, 0, 0; 0.5, 0, 0.5, 0, 0; 0.3, 0, 0, 0.7, 0; 0.05, 0, 0, 0, 0.95; 0, 0, 0, 0, 1];
ScoreProgressionStructAge18 = CalcExpectedNumTrialsToLay(LayMatrix,z0,500)
ScoreProgressionStructAge31 = CalcExpectedNumTrialsToLay(LayMatrix2,z0,500)
function OutputStruct = CalcExpectedNumTrialsToLay(LayTransProbMatrix,s0,nCeiling)
CumProbVecOfScoring = NaN*ones([1,nCeiling]);
CumProbVecOfFailing = NaN*ones([1,nCeiling]);
nVec = 1:(nCeiling-1);
T = LayTransProbMatrix’;
[eigVecs eigVals] = eig(T);
for i = 1:nCeiling
sNext = real(eigVecs*(eigVals.^i)*inv(eigVecs))*s0;
CumProbVecOfScoring(i) = sNext(end);
CumProbVecOfFailing(i) = 1-sNext(1);
end
ExpectedNumTrialsToScore = sum(nVec.*diff(CumProbVecOfScoring));
ExpectedNumTrialsToFail = sum(nVec.*diff(CumProbVecOfFailing));
OutputStruct.CumProbVecOfScoring = CumProbVecOfScoring;
OutputStruct.CumProbVecOfFailing = CumProbVecOfFailing;
OutputStruct.ExpectedNumTrialsToScore = ExpectedNumTrialsToScore;
OutputStruct.ExpectedNumTrialsToFail = ExpectedNumTrialsToFail;
end
ERRATUM: Expected number of girls with whom dude should expect to fail on way to scoring should be reduced by 1 for both models (i.e. from 15 to 14 in the “chance” model and from 14 to 13 in the “realistic”). True to ‘tard-dom, yours truly included dude’s success-girl in each of the above failure counts.