That's easy. You just take Value/IP, and you have the number you'd need to compare the value of 2 pitchers when both are healthy. And you can absolutely make an estimate on how much you should be giving in incentives based upon that number. In Sheets' case before this season, you can pretty safely estimate that he's going to pitch about 150 innings. Now that's not necessarily true, since he obviously pitched more than that. If his elbow issue had set in before it did, then he could have pitched a lot fewer than 150 innings. But on average, that's what you expect him to do. So from there, you take a 3 year average of Value/IP and multiply it by the number of innings you can reasonably expect him to pitch. Then you have what that person should be worth on the FA market. Now this is pretty fast and dirty, but it's not a bad way to guess at the true value of a pitcher. In the case with Sheets, he has about $100,000 dollars/IP value on the free market over the last 3 years. Since he's coming off an injury, that value is likely to go down. As such, the 80-100 IP a GM could reasonably expect him to pitch next year would be worth ~$6-7m. To put this in context of last season, we really could only expect him to pitch 150 innings, as that is the average of the 3 seasons before that. At $100,000/IP for value, you could reasonably expect him to put up about $15m of value. As it was, he exceeded that by over $5m. I think we got way more value out of Sheets last year than we reasonably could have expected before the season started. The extra five million was gained in the opportunity that he would pitch an extra 50 innings. In the same respect, in 2006, we could have reasonably expected him to pitch somewhere around 180 innings based upon the 3 seasons before it. He ended up pitching only 108, so we lost 72 innings of opportunity due to injury. He still had a total value that exceeded his contract, but we lost nearly 8 million dollars of true value to injury. That's opportunity cost. If you begin to value specific wins over others based upon context, then we've lost any means to quantify the argument, and it regresses to a "no, he wasn't" "yes, he was" argument.