Zito would scare the hell out of me if my team were thinking about signing him. Over the last several years he’s pretty consistently excelled against the teams with weak lineups and gotten pounded by the teams with strong lineups. You can say that about a lot of pitchers, but the splits are pretty well defined in his case, independent of home/away or anything else. It’s a good way to rack up a decent regular season with a bunch of wins, but… well, shutting down the Twins and then getting pounded by the Tigers in the playoffs was a pretty good representation on how he’s pitched in general the last few years. For example, this past year:
2006
Zito vs. Top 7 AL Teams in Runs Scored: 103.1 IP, 66 ER, 5.76 ERA
Zito vs. Everyone Else: 117.2 IP, 28 ER, 2.14 ERA
This is a pretty consistent trend throughout his career, more in some years, less in a couple of others. Particularly, less in his first couple of years when he had a much higher strikeout rate than he has had recently. My layman’s guess is that the lower strikeout rate is indicative of him becoming the kind of pitcher who relies much more on location and finesse, and that that sort of thing tends to not work as well against extremely patient hitting teams, which the top scoring teams usually are. Whether that’s right or wrong…
… this is a trend that you’ll see from a lot of the pitchers in the league, sure. The best hitting teams are going to hit pitchers harder than the worst ones - it only stands to logic. You WON’T see that trend, however, in the few true aces around MLB. Guys like Santana, Carpenter, Halladay, even a Schilling… sure, they’re on some days, and off some days. But when they’re on, they aren’t getting hit around, no matter who the opponent is. They will likely show a split where the better hitting teams score a bit more on them, but it won’t be anywhere near that drastic. The drastic splits are things you see on sort of second-tier guys like a Radke, 2006 Randy Johnson (he had some good games against the AL Central, but almost all the poundings he took were against the good teams in the AL, and he dominated most of the weaker ones), even Verlander (he got a lot of pub for a quality rookie season and his velocity, but his K ratio was actually relatively modest and he got pounded by the big guys) - these pitchers all end up with stats that are very useful for your team, but they are effectively number 2 guys and iffy in the playoffs.
So I guess what I’m saying is I don’t think Zito is worth “ace” money for a team like the Red Sox or Yankees that is facing the AL East all season and then demands playoff success. He’s a quality pitcher, and by no means am I saying he’s BAD… but he isn’t the guy you want starting game one, and he’s going to end up being paid like that guy.