In terms of stolen base runs, Brandon Thomas accounted for nearly 99 percent of his team’s stolen base runs.
In the sabermetric community, weighted Stolen Bases, or wSB, measures the amount of runs a player contributes to his team, compared to the average player. It is a component of the baserunning aspect of Wins Above Replacement(WAR).
The formula measures how successful a player steals bases along with how many times a player cost his/her team when he/she were caught stealing over the amount of chances the player had in terms of reaching first base via walk, single, and hit by pitch.
The wSB formula goes as follows:
wSB = (SB * runSB) + (CS * runCS) – (lgwSB * (1B + BB + HBP – IBB)) where SB = stolen bases, runSB = run value for stolen bases, CS= times caught stealing, runCS= run value for getting caught stealing, 1B = singles, BB = walks, HBP = hit by pitches, and IBB = intentional walks.
lgwSB is the league average stolen base runs and it is computed as follows:
lgwSB = (SB * runSB + CS * runCS) / (1B + BB + HBP – IBB)
The run value for a stolen base is set a 0.2 runs each season for simplicity, while the run value for caught stealing is another formula based upon the runs per out. The formula is:
runCS = – (2 x RunsPerOut + 0.075)
Runs Per Out is simply runs scored divided by the number of outs.
In the Frontier League in 2017, 5,568 runs were scored while 29,814 outs were made. Divide the two, then multiply by 2 and add 0.075 and the answer is a -0.4485 run value for getting caught stealing.
As for the lgwSB, 1197 bases were stolen, there were 329 instances of someone getting caught stealing, 7000 singles were hit, 4286 walks were allowed, there were 621 instances of a hit by pitch, and 115 intentional walks were issued. Follow the formula and the lgwSB equates to 0.007789 runs.
Now all constants are set, we can look at an individual player’s wSB, specifically Brandon Thomas of the River City Rascals.
Thomas stole 49 bases and was caught 5 times, while hitting 38 singles, walking 56 times, getting hit by 12 pitches, and being intentionally walked twice.
Plug in the numbers as such:
(49 * 0.2) + (5 * -0.4485) – (0.007789* (38 + 56 + 12 – 2)) = wSB = 6.75
Brandon Thomas by himself adds nearly 7 runs from stolen bases.
What makes that number look even more impressive is that the Rascals as a TEAM contributed 0.11 runs from stolen bases(not including Brandon Thomas).
Thomas is a whole 5 runs better than the next best teammate, Josh Silver.
How about a graphical representation?
That data point in the far right? That’s Brandon Thomas.
Other players, like Mike Jurgella, stole 16 bases, but contributed negatively to his team in wSB.
Recall in an earlier article, I mentioned that Brandon Thomas lead the Frontier League in strikeouts but had an above league-average wOBA, meaning he still provides value as a hitter.
When Thomas does reach base, he provides a ton of value in terms of stolen bases.