One of the frustrating things about looking at advanced metrics is that most of us have a difficult time deciphering what is the in the secret sauce. I talked to a former writer at Baseball Prospectus once. He described the phenomenon very uniquely. He said there were sharp knives and dull knives. The dull knives can use the data and sometimes explain the data to other dull knives, but the sharp knives were the ones that manipulated data. One of the things I can do in this space is break down different numbers as best I can, so you can digest them.
We’ve talked about catcher fielding and there are few things more exciting. We are finding out more and more about pitch framing. So much of what catchers do is wrapped up in that. So, fielding value is likely to be pretty fluid. Conversely, we have a very good handle on offense. We can compare guys with their contemporaries and throughout history. Below are five metrics we will use throughout our look at various players as long as this website is up.
OPS+- OPS stands for on base percentage plus slugging percentage. It is crude, but it is said to explain 90 percent of the variance in what hitters produce. OPS+ compares players with the league average after you distill out the effects of their home ballpark and the league norms that particular season (or length of career). 100 is considered average. Anything over 100 is above average.
wOBA—This stands for weighted on base average. It measures a player’s overall accomplishments per plate appearances and expresses it like an on base percentage. The average varies over time, but usually .330 is a benchmark.
wRC+— This stands for weighted runs created plus. It takes a player’s runs created and measures that against their home ballpark and the era they play in. It then calculates to be against an average of 100, so that it is measured on a per plate appearance basis.
OW%– This stands for offensive winning percentage. It assumes league average offense and league average pitching across the board and creates an offense of only that hitter. The runs created with nine of those players is compared with average runs allowed to create a Pythagorean winning percentage. Obviously a .500 OW% indicates a league average hitter.
BPO—This stands for bases per out. It is calculated by adding total bases with walks and hit by pitches and then divided by outs made. Outs are the life blood of the sport, so the more bases you can produce per out the better offensive player you are.
One of the things we should mention is that there Is a consistent occurrence we see across the board is that the standard deviation is dropping as we advance through history. Some of this is natural given the expansion to 30 teams from 16. Some of this happens through improved scouting and a league wide approach to data. This doesn’t have as much of an effect on statistics like WAR and win shares because those compare to the replacement level player in that era and that’s a sliding scale. The numbers above are more stagnant, so while they do adjust for a player’s era, the earlier players will have a bit of a mathematical advantage.
You can split these metrics into two categories. There are those were players are more directly compared to players from their own time and there are those where they are compared to all-time. OPS+ and wRC+ are all-time statistics. They are extremely similar except wRC+ includes base running, so it might be a little more accurate. The other metrics more directly compare players with their own time. Cochrane caught during the Live Ball Era when offensive numbers were outrageous. So, his wOBA, OW%, and BPO might be higher than Mike Piazza, but comparatively Piazza was probably better.
I think the big take away though is that Roy Campanella belongs in this group when you start looking at him on a per plate appearance basis. He is fourth in bases per out, fifth in offensive winning percentage, seventh in wRC+, fifth in wOBA, and seventh in OPS+. So, he finishes around the middle of the pack in all of the categories.
We could stop here, but one of the new waves of the fantasy game is daily fantasy sports. It has become a billion dollar plus industry that has even involved government as they decide whether to consider it gambling or not. The idea is that you pick a team with a cap of money and those players compile points for that day. So, instead of a standard five categories like most fantasy leagues, each event is awarded positive or negative points. So, we will show off our own historical example to see which catcher would have been the best daily fantasy baseball player of all-time. Below is the formula we will use.
Total Points = Total Bases + Runs + RBI + SB + BB + HBP – SO – GIDP – CS
To make matters a little easier, we will combine stolen bases, walks, and hit by pitches into a combined positive category. We will combine strikeouts, grounded into double plays, and caught stealing into a negative category. In order to account for differences in career length we will also look at their total points accrued per game.
So, while these numbers don’t carry the same weight as the others, they are interesting. Some problems always arise. MLB didn’t always keep official records of statistics like grounded into double plays, so we had to estimate for guys like Cochrane, Dickey, and Hartnett. That beings said, the inclusion of numbers like strikeouts made this a little less predictable than the rest of the numbers.
There can be little doubt that Mike Piazza was the most valuable offensive catcher of all-time, but we should take a minute to acknowledge the greatness that was Mickey Cochrane. While his career was relatively short and his defensive value was not stellar, there might not have been a better hitter at the position in the history of the game.