Some Perspective on the Impact of an Impact Bat

Pena could be a potential upgrade at first base - MRHSfan,
A large segment of the Pirates fan base, energized by the team’s competitive play, is eager to see the team trade for an impact bat before the July 31 trade deadline. Over the past few weeks, it has been difficult to turn on the radio without hearing a caller state that Neal Huntington should deal whatever prospects are necessary to acquire someone like Carlos Beltran or Hunter Pence. Despite the improved play, the Pirates lineup has been underwhelming, and a guy like that would be a clear upgrade. That being said, it is important to keep the expected impact of adding a big bat in perspective.

To do this, I am using ZiPS. ZiPS is a projection system created by Dan Szymborski, and it is constantly updated at FanGraphs throughout the season. As a result, we can estimate how a player will perform over the remainder of the season, based on his production to date both this year and in previous seasons. The next step is converting that production into runs above or below average, and comparing the various players already with the Pirates to those potentially available in a trade.

I decided to look at a few of the names that have been discussed over the past few weeks or so. This is meant to be a general look at the situation, so I included Carlos Beltran even though he has already been traded to the Giants. I estimated that each player would accumulate 225 plate appearances in an everyday role down the stretch (3.75 plate appearances per team game).

Garrett Jones 0.257 0.322 0.435 0.329 2.9
Jose Tabata 0.282 0.344 0.391 0.329 2.9
Steve Pearce 0.257 0.325 0.429 0.328 2.7
Lyle Overbay 0.240 0.322 0.397 0.318 0.8
Matt Diaz 0.267 0.312 0.406 0.313 -0.2
Alex Presley 0.266 0.316 0.392 0.311 -0.6


Carlos Beltran 0.276 0.373 0.474 0.371 11.2
Carlos Pena 0.229 0.352 0.482 0.362 9.4
Hunter Pence 0.286 0.333 0.470 0.351 7.2
B.J. Upton 0.245 0.335 0.412 0.337 4.5

As you can see, all four external options would be upgrades over the players already under Pirates control. Generally, ten runs is equivalent to about one win, so the maximum upgrade in this case is around one win. A single win is pretty significant at this point in the season, particularly for a team in a close divisional race. The Pirates are currently on pace for 84 wins this year. Assuming they maintain that pace (this is far from certain, but in a hypothetical sense), bumping that up to 85 wins could certainly turn out to be significant. A one-win improvement is not very important for a team that wins 57 games; for one battling for a playoff spot, it is huge. In other words, the Pirates absolutely should be looking for ways to upgrade the offense for the stretch run.

However, is it worth blowing up the farm system for a one-win improvement? The system has improved the past few seasons, but the organization is not yet in the position where it can start shipping out loads of promising minor leaguers. There are still plenty of holes on the major league team that will need to be filled by prospects over the next few years. A one-win improvement could potentially be the difference that allows the team to sneak into the playoffs, but it does not guarantee anything. It may just take the Pirates from 84 to 85 wins, still leaving them a few games back in the NL Central race.

The Pirates should certainly be trying to upgrade their feeble offense over the next few days. But if you find yourself falling into the “trade whatever prospects it takes” mindset, keep in mind that any player coming back in return is not going to make this an above average offensive team by himself.


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Robert A Bishop

Not that I would advocate it, but giving up Allie or whatever would not constitute “blowing up” the farm system.  The additional revenue and win(s) that a Beltran-type player would bring in allow them to bid for another Heredia-type next year, so there’s no need to exaggerate the negative component.

Also, I think its disingenuous to imply that replacing Overbay/Diaz/Jones/Alvarez/Paul/D’Arnaud/other .280 OBA guy with a legit bat would equate to 1 win considering they will be in 30 1-run games between now and the end of the year.  Advanced metrics are great, but no one would dispute that Beltran would result in more than 1 win over Overbay over the next 250 at-bats—especially considering the solid pitching that keeping games competitive.


Well, actually, you can dispute that. The Pirates, through 103 games, have played 27 one-run games; it seems unlikely, at best, that they’d play 30 in their final 59.  The use of advanced metrics isn’t “disingenuous”; it’s using research based on considerable in-game data.  To paraphrase something Bill James wrote nearly 30 years ago, we know things through data and testing that data; things we just “know” are close cousins to things you get on the bottom of your shoe in a barnyard.

Corey Barcus

What talant, they have very, very little minor league talant. MAYBE 3 or 4 real ML prospects. I think you over esimate the Pirates farm system.


Agree and disagree.

We have talent, but are EXTREMELY top-heavy.  When you go down the prospect lists, the first (and really only) cornerstone trade piece would be Starling Marte.  The players who are above Marte are too valuable to the franchise, the players below are under-performing or not great prospects.  And another thing to realize is that Marte isn’t much more than an above-average prospect.  22yo in AA with a horrendous K-BB… yeah, shouldn’t be too highly-touted.

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