The Snow Index Project, Part 2
The development of a new statistic, step-by-step.
A 162-game season begins this week. Each team will play out better than 10000 at-bats between offense and defense, enough that one would think that any “sample size” problems would sift themselves out, yet every year we seem to find a team or two commonly believed to be “lucky.”
I know this territory isn’t exactly uncharted, and I’m certain others smarter than me have taken a swing at it. I’m also aware that if anyone properly quantified luck in this situation, they could probably make themselves quite wealthy in Vegas. I don’t think I’m in a position to write the “ultimate quantification of luck in baseball,” but I would like to offer my own take on it, the RPSR.
The actual formula I’m starting with is rather simple:
Runs - Home Runs
Hits + Walks - Home Runs
I’m calling this formula the Run Production Success Rate, or RPSR. Simply, it measures how often a runner who gets on base, but doesn’t drive himself in, gets driven in. Several factors could make this number go up or down, such as:
Extra base hitting: Home runs are eliminated from the equation in the beginning, but doubles and triples are still in. A runner who starts his trek towards the plate from second or third has a better chance of getting there.
Speed: Cecil Fielder would be a little harder to score from first than Carl Crawford. Hell, in a race from first, Cecil Fielder might cross home plate behind Rocco Baldelli on crutches. Base stealing is an obvious and quantifiable factor, the ability to take the extra base or stay out of the double play is a little harder to lock down.
Power: On a team like the 2004 White Sox, that hit a bunch of home runs, getting on base at the top of the order was sometimes all that was necessary, as it gave Lee, Ordonez and Co. the chance to mash non-solo home runs.
Lineup balance: Tony Womack might hit .300 in the 9 hole for the Yankees this season. The Royals may have three regulars with OBP under .300. (3 players had better than 200 PA and OBP that low last season.) So when the middle of the Yankees lineup gets on base, there’s a chance the bottom of the order won’t kill the rally. When Mike Sweeney got on base for the Royals, the odds of him being driven in were minimal at best.
“Little ball”: Getting a runner on first and sacrificing him into scoring position increases the odds of getting one run, and simultaneously eliminates the chance of getting anyone else on base, thereby affecting both sides of the equation.
Luck: Sometimes the dice just falls on the right side. Bloop singles, errors and poor decisions by your opponent happen, and while capitalizing on them takes some skill, having them happen at the right time can cause more success than a good decision could have.
Extra base hitting is easy to measure, and can be eliminated from the equation as it is in the table below. The extra base hit ratio (XBH) is also pretty simple:
Doubles + Triples
Hits + Walks – Home Runs
This gives you a percentage of times on base that aren’t home runs, but are extra base hits. If a team has a high XBH ratio, it makes logical sense that they should also have a high RPSR. In the cases where there are large differences between the two, one has to take a look at the other factors listed above. If the difference can’t be explained by one of those factors, it’s possible you have a luck situation on your hands.
The first number in the table below is RPSR, the second is XBH Ratio. The next two numbers are the respective team rankings in each statistic. As mentioned above, a team with a high number in one column should have a similar number in the other column. A positive number under “Difference” means a team did better than their XBH Ratio would imply. A negative implies underachievement.
average team speed (6 players with 15+ SB) certainly helps, as does a team
strategy which seems to favor little ball.
Tied for AL lead in HR, Aaron Rowand and Willie Harris both show good speed and R/on base ratios
Led AL in hits, but appear to have gotten a disproportionate amount of luck driving runs home
million payroll, balanced lineup with no dead spots means less runners left
on base at the bottom of the order.
weak bottom of lineup means most scoring opportunities come from the top of
the order, where the chance of scoring is better.
Led AL in triples, but that’s not enough to explain this big of a gap.
NL overachiever, but good team speed and strong lineup throughout make them
only a small surprise.
good team speed and some good luck, the Dodgers only scored 761 runs, 9th
of 16 in the NL.
the obvious reason they’re above break-even, but Juan Pierre’s 24 CS may be
part of the reason they aren’t farther above the line.
unspectacular, lineup was solid throughout with no black holes, causing a
receiving some luck, still only scored 680 runs. To get to 85 wins with this
lineup and defense, they’d need a team ERA of 3.70.
to Pittsburgh. Overachieving makes this lineup only slightly less pathetic.
Crawford scored 104 runs despite just 210 times on base. Not too many hitters
can match that.
regulars with 10+ HR, lots of doubles, and a lot of runs driven in.
about as often as they deserved to, but didn’t provide as many opportunities
as they should have.
in AL in team OBP and slugging, average luck.
average speed without Beltran, average power, average result.
again, but solid across the board.
pitching and defense are what wins games in October, why aren’t we
celebrating the 4 time defending champion Twins?
can you really complain that much about this offense?
speed, but didn’t score as often as would be expected from a team that led
the AL in doubles.
Bonds got on base 367 times by himself, 45 times via a home run. In those
other 322 chances, he was driven in just 26% of the time.
extra base hits, but no speed and 1153 K’s left lots of runners on, too.
Wilkerson scored 112 runs last year, second was Endy Chavez with 65.
Thirteenth or worse in every offensive category. And it’s possible they
should have been worse.
balanced, solid at every position but overachieving nowhere.
find a new way to make outs on the basepaths everyday.
the 2004 Mets listed as underachievers should come as a shock to no one.
avoided more strikeouts (1335) than hits (1380). It’s hard to move runners
over like that.
.310 OBP assured
that when runners got on, ensuing hitters quickly made outs to insure they’d
only Arizona in runs scored, last in batting average, and second to last in
home runs, but Lyle Overbay can really crack a double.