Hart's Win Share Statistic

Andrew Hart's Win Share Statistic is a statistic created by Andrew Hart that attempts to calculate how valuable each player on a team was to his/her team's success. The statistic combines a measure of positive contribution with a calculation of how much of a negative contribution that a player's negs make.

Calculation

Calculation of the statistic is moderately time consuming. To begin, one calculates each player's individual contribution.

The individual statistic is simply (player's positive contribution) - (player's negative contribution).

The positive contribution is a measure of points created - ten points for getting a tossup and an average of (bonus conversion) bonus points on the ensuing bonus. To calculate the positive contribution, multiply the player's tossups answered by 10 and add the product of the player's tossups answered by their team's points per bonus.

The negative contribution measures how much a player's negs hurt his team, comprised of two parts: first, the total point value lost due to the negs, and second, an estimate of points cost by preventing teammates from later buzzing with the right answer. To calculate the negative contribution, multiply the team's tossups answered by (teams tossups heard/players tossups heard), and subtract the player's tossups answered. Divide from that the product of (player's tossups heard-player's tossups answered), the player's negs, and the sum of the team's points per bonus + 10 and the player's negs times 5.

For an easier representation, let t=player's tossups answered, o=team's tossups answered, s=player's tossups heard, u=team's tossups heard, n=negs, and b= team points per bonus.

Positive contribution = 10t+tb.

Negative contribution = ((o*(s/u)-t)/(s-t))*n*(b+10)+5n

Add each player's individual contribution, and divide each player's individual contribution by the team total to calculate each player's percentage contributed.

Multiply that by the team's win percentage to obtain the number of win shares. Alternatively, one can multiply the player's percentage contributed by the team's number of wins to calculate the number of wins that player contributed.

Links

The post in which the statistic was introduced

An excel spreadsheet which calculates the win share for an individual team