The All-Star Game is behind us, which means everyone now is paying attention to the coming trade deadline. The appeal, I think, is about two things: One, we’re just engineered to crave roster change. Two, we’re led to believe this is when winners are made. Or at least, this is when winners do something that puts them over the hump; and this is when losers can try to collect prospects. For the next week and a half, the trade deadline will be the most important thing. Regardless of whether it deserves that status, this is the annual routine. Right now, it’s all about possible moves.

Related to that, Bob Nightengale caused a stir with his report that the Detroit Tigers might sell — and might therefore sell David Price. It’s significant not just because the Tigers don’t usually sell, but also because Price is an ace, and available aces are diamonds every July. Consensus is that there’s no sexier addition than a No. 1 starter, which is why there’s also so much attention on Johnny Cueto and Cole Hamels. And Jeff Samardzija and James Shields, and so on. The idea is that a front-line starter becomes even more valuable in the playoffs. And people are inclined to believe that, in the playoffs, pitching is what matters most. So this time of year, the supposedly most desirable pieces are the best and most durable arms.

This calls for a simple analysis. Actually, this calls for a very deep and thorough analysis, but I’m not very good at those. A simple analysis is the fallback. Front-line starters have been traded midseason before. What’s happened with the teams that got them?

I already warned you this would be simple. I examined the 20-year window between 1995 and 2014, covering the Division Series era. I found all the starters who pitched for multiple teams, and then, as a judgment call, I decided on my front-line-starter group. For each pitcher, I multiplied his FIP- by 2, I added his ERA- and I divided by 3. I then put the cutoff at 85 — roughly 15% better than league average. I know it’s arbitrary, but a line had to go somewhere, and this method captures all the good arms.

Ideally, I would’ve separated the pitchers by how they were projected at the moment they were traded. I couldn’t do that, so this is a proxy. Once I had the pitchers, it was just a matter of looking at the teams to which they were dealt. The graph below shows how those seasons ended. These are seasons in which the team added a front-line starting pitcher in June or July. All the teams, at the time of the moves, were competitive.

Data:

Through this method, I found 22 trades that were made by 21 teams. If that’s a little confusing, it’s because last year’s Oakland Athletics added front-line starters in two separate deals — adding Jeff Samardzija and then Jon Lester. I don’t want to bias by double-counting. Of the 21 teams that added good starters, 17 advanced beyond the end of the regular season. Two were eliminated in single-game eliminations. Nine were eliminated in the division series. Four were eliminated in the championship series. Two lost the World Series. Which means that none of the teams actually won the World Series.

It’s not that World Series-winning teams haven’t added starting pitchers. Last year’s Giants swung a midseason trade for Jake Peavy. But Peavy wound up with a below-average FIP and an average ERA. When championship teams have added starters, they’ve been of the second- and third-tier varieties. The teams adding the big guys have made some noise, but of late they haven’t hoisted a trophy.

When you’re selling a front-line starter, you’re selling the idea that said starter could carry a team through October. Look at what Madison Bumgarner just did. It’s an appealing thought, and it’s founded in truth. But you can look at last season for counter-evidence. Neither Samardzija nor Lester could save the A’s, which lost a one-game playoff in which Lester got the ball. After the Tigers added David Price, they went on to get swept in the first round. Go back further: The Angels missed the playoffs entirely despite picking up Zack Greinke. Two years in a row, Cliff Lee joined a series-bound team and lost. Maybe the ultimate addition was Randy Johnson to the Houston Astros, in 1998. Houston lost the NLDS, 3-1.

The point isn’t that it’s senseless to add a good starter. That would be a stupid point. Good players are good and good players help. The point also isn’t that you can’t win a World Series if you trade for a good starter. That would be an even stupider point. Additions shift the probabilities. It’s all about the probabilities. And, hey, Curt Schilling won the World Series with Arizona, the year after getting traded there midseason. There’s no reason why a good pitcher wouldn’t be awesome to have, and there’s no reason why the good pitchers available today couldn’t help teams in the market for arms.

But it’s also important to be realistic about the significance of a midseason addition. It’s important to be realistic about a team’s chances of winning it all, even given a postseason berth. A whole lot of teams play in October, and they’re all pretty good. One player can mean only so much. So you can understand why front offices hold on tightly to their prospects, even when they have a shot at a title. After all, those prospects could be a part of several shots in the future. Exchanging them now could mean a couple percentage points. No trade is ever about locking up a World Series. Such certainty could never exist.

As a seller, you want to push the idea of the ace who puts a team on his back. More realistically, you’d want to push the idea of the ace who simply helps a team to the playoffs. But it’s not on the salespeople to be realistic, I suppose. It’s the buyers that most need to be informed.