Let's look through another lens.
Better WHIP/Worse ERA A.L.
|1||Carlos Silva||153 1/3||6.46||1.598||69||20||-6||-19||3||3||3||13|
|2||Brian Bannister||182 2/3||5.76||1.495||113||29||-6||-9||5||7||1||18|
|4||Boof Bonser||118 1/3||5.93||1.479||97||16||-5||-9||6||5||1||-5|
|5||Kevin Slowey||160 1/3||3.99||1.154||123||22||-5||18||9||6||4||2|
|6||Javier Vazquez||208 1/3||4.67||1.320||200||25||-5||7||20||15||13||26|
|7||Josh Beckett||174 1/3||4.03||1.187||172||18||-5||17||26||30||27||33|
|9||Scott Feldman||151 1/3||5.29||1.434||74||22||-4||-5||-7|
|11||Andy Sonnanstine||193 1/3||4.38||1.288||124||21||-4||12||6||5||2||-3|
|12||Nate Robertson||168 2/3||6.35||1.660||108||26||-4||-20||4||6||3||-0|
The 14 pitchers above are the American League starters (100 IP or more) who had a $4 or greater differential between when they earned (or lost) in WHIP and what they earned (or lost) in ERA. Carlos Silva, for example, lost $7.99 in WHIP and $14.21 in ERA. Looking at a more positive example, Tim Wakefield made $5.94 in WHIP and nine cents in ERA.
Why should any of this concern us?
In theory, pitchers whose performance in WHIP outshines their performance in ERA should be due for a rebound the following year. Pitchers who surrender "x" amount of base runners should allow "y" amount of runs.
In practice, as we all know, it doesn't work this way. Some pitchers are simply more inclined to give up more runs per base runner allowed. Fly ball pitchers are more likely to wipe the bases clean with a home run than keeping the damage minimal by keeping the ball in the park. Some pitchers are unluckier than others (the BABIP stat is the modern reflection of this "luck").
As a group, the pitchers above are all unlucky. The average pitcher purchased in A.L. Rotisserie leagues put up a 1.345 WHIP, so this group - despite the presence of megaton bombs Robertson and Silva - is only slightly below average in WHIP. However, the league average ERA is 4.14, so this group was over three-quarters of a run over the league average in ERA.
(It should be pointed out that these averages are for the typical pitcher purchased in Roto leagues. The average American League pitcher put up a 4.35 ERA and a 1.392 WHIP.)
As individuals, though, these pitchers are all over the place. Shave another .74 off of Ervin Santana's ERA, and you've now got a pitcher with a 2.75 ERA whose earnings jump from $29 to $35. This doesn't even account for the wins Santana might have picked up in the small handful of close games where giving up a run less may have made a difference.
Do the same thing for Silva or Robertson, and they're still pitchers you don't want gracing your roster.
For the most part, the market recognizes this. Beckett and Vazquez are the only pitchers the market really wants, and there's a huge drop-off from Vazquez's average $20 salary to Slowey's $9 (the next highest salary on the list).
And I'd say that the market's reticence was correct. Beckett's season was definitely unlucky (compare to his 2005: 3.38 ERA, 1.18 WHIP), and Santana had some bad luck as well. Everyone else on this list are the kind of strike throwing, soft tossing kind of guys you'd expect to be here. Or they were just bad.
Worse WHIP/Better ERA A.L.
|1||Daisuke Matsuzaka||167 2/3||2.90||1.324||154||12||8||25||23||21||18||13|
|2||Felix Hernandez||200 2/3||3.45||1.385||175||17||7||12||24||24||24||14|
|3||Jon Lester||210 1/3||3.21||1.274||152||14||5||24||7||9||5||1|
|4||Joba Chamberlain||100 1/3||2.60||1.256||118||5||5||12||13||9||16||10|
|5||Ryan Rowland-Smith||118 1/3||3.42||1.369||77||13||4||8||1|
|6||Edwin Jackson||183 1/3||4.42||1.505||108||23||4||4||1||2||-19|
|8||Cliff Lee||223 1/3||2.54||1.110||170||12||3||43||1||3||-7|
|10||Mark Buehrle||218 2/3||3.79||1.335||140||22||3||16||8||10||13||17|
|12||Sidney Ponson||135 2/3||5.04||1.607||58||14||2||-5||-7|
|13||Zack Greinke||202 1/3||3.47||1.275||183||21||2||19||11||11||7||11|
|14||Kevin Millwood||168 1/2||5.07||1.595||125||18||2||-7||3||4||6||-7|
These are the first list's 14 counterparts. And there's no doubt this is a lucky group; despite a 0.39 higher WHIP, these pitchers give up over a run less per nine innings.
Lucky or no, this is a more successful group of pitchers for our purposes. They out earn the WHIP group on average by a $10-2 margin. Only Batista, Ponson, and Millwood put up negative earnings, while half of the WHIP group did.
Obviously, this is once again a product of ERA. Fewer runs allowed means more opportunities to win games and earn money via that avenue. Cliff Lee, who nearly put up the same WHIP as Ervin Santana, is "only" a $36 pitcher if you inflate his ERA to 3.30, which again doesn't take into account the wins Lee might have lost with a lesser ERA.
It's a little puzzling that the market pays this group of pitchers $2 per pitcher more despite the fact that these pitchers earned $5 per pitcher less in 2007. It can't just be the negative earnings; both the WHIP and ERA sorts feature six negative earners from 2007. It can't just be the strikeouts; getting seven more whiffs per pitcher isn't a lot - not even in 5x5 - to justify such aggressive bidding.
The one number that jumps out in the second group are the HR. Allowing seven HR less per pitcher is a big deal - especially since the strikeout differential is virtually nonexistent.
You'd expect to see a lot of big-time ground ball pitchers on the ERA list, and four of the top 10 in the A.L. last year - Ponson, Hernandez, Chamberlain, and Buehrle - are there. There's some nice symmetry with the most fly ball prone pitchers, as four of them - Wakefield, Byrd, Bannister, and Slowey - cracked the WHIP list.
The question I leave you with, though, doesn't concern the past but the future.
What will these guys do next year? Were the bad WHIP guys lucky? Are the bad ERA pitchers due for a rebound?