Baseball by the numbers

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The “triple crown” statistics (batting average, runs batted in and home runs) are of little use to modern general managers.

Instead they use numbers that closely resemble the ratios corporate analysts use to assess stocks.

Key terms for hitters include:
On-base percentage (OBP) – the numerator is hits plus walks plus times hit by a pitch (all the times a player reaches base). The denominator is the total number of plate appearances, subtracting deliberate “sacrifice” bunts.
Slugging percentage (SLG) – this measures power, in terms of how far around a diamond a hitter goes at each bat. If a hitter strikes out, and hits a single and a double, he has covered three bases in three times at bat, for an SLG of one. If the double were reduced to a single, his SLG would be only 0.66.
On-base plus slugging (OPS) – this adds OBP and SLG. It is regarded as the best simple measure of a hitter’s overall worth.
Batting average with balls in play (BABIP) – this takes the batting average once walks, hits and home runs have been excluded. A very high BABIP can imply that a player was merely lucky that his hits happened to find gaps in the field, and is likely to decline over time. It is thus an important correction.
OPS+ – this measures how much a player’s OPS differed from the average for the season – either in percentage points or in standard deviations.

More complex measures that cover the totality of a player’s contribution include:
Win shares – derived from a Pythagorean projection of the number of wins a team will enjoy from a given differential of runs scored and runs allowed;
Value over replacement player (VORP); and
Wins against replacement player (WARP).

For pitchers ignore win and loss records. Instead, try:
Walks and hits per inning pitched (WHIP); or
Peripheral statistics – research shows that once a batter has hit the ball inside the park, what happens next is so much a matter of chance that pitchers are best assessed only on the events where nothing is left to interpretation – walks, strike-outs and homers.

GMs look for high strike-out rates and low homer and walk rates, and ignore wins, losses and runs scored.

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