Bill Braer (@CrashburnAlley) and I got into a Twitter scuffle (it was even less antagonistic than it sounds) about intra-division trading, specifically about the Blue Jays sending Roy Halladay to the Yankees for something like Joba Chamberlain. I wondered aloud why organizations were so scared to do it and Bill's convinced it's just not the smart move to maximize playoff probability. Eventually, having a debate 140 characters at a time became stupid (at least to Bill) so he wrote about his thoughts at his blog. I'd tell you to go read the whole thing over at his site, but since I know not everyone will do that, I'll cherry pick his points that I want to disagree with here: "Between 2002-08, Roy Halladay has been worth over six wins above replacement per season. As of right now, the Yankees have accrued 19 WAR in 88 games and the Blue Jays have accrued 12.4 in 90 games, putting them on pace for 35 and 22 WAR, respectively. Prorating Halladay’s average production for the rest of the season, if the Jays traded him right now to the Yankees, they would be losing about 3.3 WAR and the Yankees would be gaining about 2.7 WAR. Overall, that’s a 6-WAR shift, or about 10.5% of the WAR the teams are on pace for. That’s without accounting for players the Blue Jays acquire and contribute during the season. If the Jays simply traded Halladay out of the AL East, they would only have to worry about losing the 3.3 WAR as opposed to another team also picking up 2.7 WAR on them." To me, that seems overly focused on 2009 (and 2010), the years Roy Halladay is under contract. Sure, handing him to the Yankees will hurt double over those seasons. But 2011 and beyond matter, too. Given that any return package likely focuses on prospects or a young major leaguer, the Jays are looking at value for years to come more than current value. So what happens in 2011 if the Jays trade within the division to the Yankees? They're not just better because they have something instead of nothing, after losing Halladay to free agency anyways. They're even more better than the Yankees because they've taken something from them. Maybe it's Joba Chamberlain or Austin Jackson. Whatever that something is, it's not just helping the Jays, but is also hurting the Yankees to have lost it. So while 2009 and 2010 might turn into a double loss by trading within the division, 2011 and beyond turn into a double win. And because the whole reason the Jays are looking to trade Roy Halladay is because they want to move value from seasons with lower probability of making the playoffs to higher probability of making the playoffs, they're leveraging their win against the Yankees to seasons when it will matter more. Now, a GM might be scared to trade within the division because a bad trade hurts more job-wise than a good trade helps, but that's a different issue.