Wins/Losses don't say much about a pitcher. If you don't have run support, you might toss 9 great innings with one unearned run and still get the loss, conversly 5 innings of 9-run-ball might be enough for the W if your batters knock in 10. Even if you compare the teams overall records, the sample size of any single starters starts is not enough to overcome statistical noise. A good W/L record on a otherwise sucky team might sound impressive, but even the worst MLB team will still win one third of their games and any starter might just be lucky enough to get the starts where the bats where hot, or he'll maybe face lower rotation positioned opposing starters more often than usual, etc.
Compare Wrights W/L records and his ERA:...
http://www.baseball-reference.com/pl...righst01.shtml