Dan Haefeli, writing for the Rising Apple, builds a strong case debunking the cloud of suspicion that hangs over the head of Mike Piazza suspecting the former Met catching great of using steroids over his career.
Piazza, baseball’s all time home run hitting catcher, failed to accrue the votes needed to be elected to Baseball’s Hall of Fame in last year’s vote. Preliminary projections indicate that Piazza’s vote totals in this year’s balloting may not reach his totals from the previous year.
Met fans are familiar with the arguments Piazza’s detractors use connecting the slugging catcher with steroid use. They reason that Piazza, a big, muscular catcher, played during a time when all the big sluggers were juiced; Bonds, Sosa, McGwire, Giambi. The list goes on. Some allege that throughout his career, Piazza suffered with back acne, a symptom sometimes associated with steroid use. In their conception of the baseball world, Piazza had to be juiced, right? Wrong!
Haefeli contends that it would be hard to argue against Piazza’s batting prowess. He reports the former Met slugger ranks 45th (.237) in isolated power and 47th (427) in home runs and his .308 batting average ranks 55th, numbers that are impressive for any major leaguer but astounding for a catcher.
To debunk the suspicions of Piazza detractors, Haefeli dissects Piazza’s ISO numbers and then compares his findings with the ISO’s of other baseball sluggers known to have used steroids.
As Haefeli explains, ISO is calculated by subtracting slugging percentage from batting average and thus measures total bases beyond first per at-bat. Hitting values give singles 0, doubles 1, triples 2 and home runs 3. By adding the totals for a batter’s hits then dividing by at-bats you have a number that projects a batter’s power. Haefeli claimed the MLB, non-pitcher, average at around .160 far below Piazza’s career totals.
Rather than compare ISO career totals, Haefeli graphs Piazza’s power numbers season-by-season over his career, eliminating the 1992 season when he only amassed 79 plate appearances. The result: a fairly smooth, clear career arc. Haefeli’s ISO graph for Piazza showed gradual and steady year-by-year improvement building into a solid career prime, then dropping steadily once age and wear and tear spiraled his career into decline.
Haefeli anticipates the arguments some might make when investigating Piazza’s power stats. For example, how can Piazza defenders explain a steep decline during his age 33 season when his ISO dropped from .264 to .197, the very year after androstenedione was banned by baseball?
Here’s Haefeli’s explanation. That was the year of Piazza’s grueling groin tear, a serious injury that most expected would keep him sidelined for the season. At the time of the injury, Piazza’s ISO was a healthy .280, exactly where you might expect it to be relative to his career numbers to that date. But, Piazza, did return in late summer, and his performance was far from Piazza like dragging down his season ISO totals. It’s important to note Piazza only played in 68 games that season.
The following season when Piazza was relatively healthy, the pattern repeated itself. Piazza was Piazza during the first half of the season .297/.388/.506 with 16 HR’s, but a tired slugger’s number’s paled in comparison during the second half of the season – .200/.305/.310 with only 4 homers.
He also presented a logical explanation for Piazza’s bounce back season in 2005 when at 36, after a consistent pattern of power decline, Piazza rebounded. Trying to protect their aging slugger, the Mets dramatically decreased Piazza’s workload and as his workdays went down his power production went up. In 75 first half games, Piazza’s ISO only reached .169. His second half number soared to .272, but Piazza played in only 38 games.
Haefeli’s argument is that Piazza’s career ISO arc looks exactly like what you might expect of a baseball slugging catcher, gradual and steady improvement that stayed constant until too many games behind the plate and a career-altering groin injury sent the ISO graph line on a downward path.
In my opinion, Haefeli’s argument was most compelling when he graphed the season-by-season profiles of baseball’s proven steroid sluggers using a different color for each power hitter. Haefeli’s chart included both Piazza’s ISO season-by-season chart, and for reference purposes David Wright’s, and Craig Biggio’s too. Unlike the gentle peaks and valleys of Piazza, Biggio, and to some extent Wright’s ISO’s, the arcs of guys like Bonds, McGwire, Sosa, etc. were marked by drastically spiked highs and lows.
The visual contrast was overwhelming. Haefeli’s chart represented 31 baseball seasons with ISO’s above .300 – none recorded by Mike Piazza. Piazza’s graph was devoid of the wild, dramatic swings of the steroid using masher’s of his day.
With only soft assumptions and no hard evidence to indict Mike Piazza for steroid use, Haefeli contends baseball writer’s should use hard evidence, baseball statistics like his isolated power analysis, to make sense of Piazza’s incredible career. Those numbers present a compelling defense that concludes that it was not steroids but a unique ability to hit a baseball that was the deciding factor in Mike Piazza’s baseball success.