Pitcher Winning Percentage

I hear a lot about “kill the pitcher win”, and I wish that would happen, but something just occurred to me that might just be as crazy if not crazier than the pitcher win. A pitcher’s winning percentage (WP) is calculated as W/(W+L). That doesn’t really make sense though. A team’s WP is calculated as Wins/Games, which makes sense since that gives the percentage of wins out of games. So a pitcher’s WP should be the same, Wins/Games. The current way is Wins/Decisions, which is just the % of games won when they were awarded a decision. That’s stupid, since, if they pitched so badly or “uselessly” that they weren’t even awarded a decision by the official scorer, then why do we discount those appearances while counting losses they were awarded? It just doesn’t make any sense, and it’s not a honest representation of what happened.

For example, Clayton Kershaw has a career winning percentage of .667, having gone 98-49 through 2014. That leads all active players and is #12 on the all-time list at the moment. That only accounts for 147 of his 211 appearances. How can any honest person ignore 64 games? That averages out to about 9 games per season of his career. His real winning percentage would be calculated as 98/211, which is .464, not .667. Of course, this shows that even the best pitchers have a hard time actually gettin’ credited with winning half their games, so maybe that’s why. I don’t know. I just know it’s not accurate if you ignore games the pitcher pitched in.