Batter’s PROP Score

Who is more likely to produce when you need it? Who is better with runners on base? PROP is the acronym for a new statistic, PRoduction per OPportunity, that may measure that. In essence it is a "clutch" statistic that measures the percentage of runners on base that score from a batter’s positive plate appearance as opposed to leaving them stranded from a negative one. A player’s plate appearance can be divided into three categories as it pertains to the effect it has on runners:

RBI - A positive plate appearance (Hit, Walk, SF, Sac) that results in a runner scoring, producing one or more RBI.
LOB - A negative plate appearance (Out) that does not result in the intentional advancement of a runner, but has one or more runners Left On Base.
RK ("Rally Keeper") - A positive plate appearance (Hit, Walk, Sac) that does not score a runner but may advance them. Cannot be categorized as a RBI nor LOB.

The LOB (Left On Base) statistic is one that many misunderstand. The Team statistic LOB counts the number of runners Left On Base by a team when the 3rd out is recorded to end an inning. The Individual statistic LOB counts the number of runners left on base by a batter after an out. Runners so left can be inherited by the next batter and count as a LOB for them too. Nearly all the time the total Individual LOBs for a game are more than the total Team LOBs. A runner is not considered Left On Base if the batter has a positive plate appearance (Hit, Walk, Sac) but the runners don’t score.

The PROP statistic can be seen as a statistic that measures clutch performance with runners on base. "Who is driving ‘em in and not leaving ‘em stranded." It compares the production of RBIs in positive PAs (category 1) to the negative PAs of accumulating LOBs (category 2). Its shortcoming is that it does not consider category 3, the RKs, where a rally is kept alive through a positive PA. A hitter may be great in this area, but there is no way to measure it. The formula is as follows:

((RBI-HR)/((RBI-HR)+LOB+GIDP))*100

Notes:

"RBI-HR" - The RBIs produced from a batter scoring on their own home run is removed, as the batter was not a runner when they had the plate appearance.

"(RBI-HR)+LOB" - represents all the runners measured in the statistic

"+GIDP" - these are added, as they represent an out where a runner is erased on a negative PA and would not be included in the LOB total. Any run scoring on a GIDP would also not be counted as an RBI.

In general, as a player’s PROP score is a percentage, here is a guideline:

PROP    30.0+           Excellent

              25.0-29.0     Good

              19.0-24.0     Fair

              11.0-18.0     Poor

            <11.0             Pathetic

It is also valuable to look at a player’s RAB statistic, or Runners per At Bat, that shows on average how often the runners on base for the PROP statistic appear. The formula for RAB is:

((RBI-HR)+LOB+GIDP)/(AB+SF)

The numerator contains the same info from the PROP denominator, and is divisible by At Bats. SF are added to At Bats to account for plate appearances that had an RBI. Minor plate occurrences are not included that have minimal effect, i.e. bases loaded walk or HBP, on base by error, etc.

Those batters with high RAB (come to the plate often with runners on) and low PROP (produce more often a negative result than a positive with runners on) are dragging a team down. While those with a low RAB and a high PROP need to play more often or need a new spot in the batting order to give them more opportunities. A batter with a low AVG but high PROP are producing more with runners on base and are still valuable. Conversely, those with high AVG and low PROP are not getting their knocks at the critical time (see RAB for how often those critical times are) and if not a lead-off man may need to move there.

All in all, PROP is not the greatest stat and has its shortcomings, but it is still a good indicator of who is coming through at the right time.