On Base Percentage (OBP) plus Slugging Percentage (SLG) produces OPS, which can be a big, impressive number. However, it has been known for over sixty years that adding OBP and SLG together overstates and disfigures the value of each as an individual statistic. The basic problem is that they both include Hits.
In an earlier Ezine Article concerning the current MLB strikeout epidemic, the formula published in a 1954 edition of Life magazine by Hall of Fame General Manager, Branch Rickey, GOODBY TO SOME OLD BASEBALL IDEAS was offered to indicate how he valued strikeouts. He also came to definitive conclusions regarding OBP and SLG.
The formula for team offense included three, "measurable ingredients," OBP, SLG, and "clutch," which he said, "Is simply the percentage of men who got on base who scored." The question he had to answer was, "But how do they fit together?" He concluded that OBP and clutch went "hand in glove with runs scored, but extra base power had a lower correlation." His dramatic devaluation of extra base power, which followed, is a direct contradiction of today's approach to hitting.
Since both OBP and SLG did include Hits, he subtracted them from SLG to arrive at "isolated power" which he had "used for years" to evaluate players. Even then, he had to "give extra base power less importance" to make the formula work. To that end, only three-fourths of the percentage was utilized to arrive at a "margin of error of 2%" when the formula was correlated with runs per game, per team, for the previous 20 years. While "isolated power" has recently again raised its head in the media, I have not seen it incorporated with other statistics to produce a reliable, useable number.
Rickey's next step was to apply the formula to individual hitters. He concluded that "clutch" was "strictly a team figure." Adding OBP to "isolated power" he listed the 25 greatest hitters from "1920 the year the lively ball came into use" through 1953. The top five were Babe Ruth, .752; Ted Williams, .702; Lou Gehrig, .666; Jimmy Foxx, .642; and Rogers Hornsby, .634. However, he admitted that # 23 – Ty Cobb, .542; "deserved to be higher because he beat you with more than his bat."
That statement about Cobb is the problem with these numbers. If batter A hits 30 more doubles than batter B he has that number included in his SLG. If batter B has 50 more net stolen bases than batter A, he receives no credit for adding those extra bases. If batter A grounds into 15 more double plays than batter B, because of B's foot speed, where do those lost bases show up? Also, batter B may be able to go 1st to 3rd on a single to the outfield, or score from 1st on a double when batter A cannot. Bottom line, the totality of the speed quotient is, and always has been, missing from the statistics that evaluate a batter's offensive productivity.
Another statistic to consider is the number of non-productive outs a batter has, aside from caught stealing and double plays. With the strikeout epidemic continuing at a record pace, the differential between batter's strikeouts should also be considered as part of the calculations. No runner reaches base, no runner advances, or scores, on a strikeout. It has no potential value. None! Until a stat is devised that accounts for all negative factors, as well as positive, any formula will be incomplete.