Is there any hope for Bill Hall to return to a decent option at any position, or fetch a return in a trade? Everyone thought his 2007 was an outlier in what was going to bounce back to a solid big league career. So what happened?

As I wrote in the Corey Hart fanpost, there are three things that could have happened to cause a player to suck:

1. Actual talent level or approach to the game changed

2. Previous success was either fluky or unsustainable

3. Recent lack of success is result of fluky or unsustainable properties

So with some time here on a Sunday afternoon, I'll see what I can find about the subject.

So we'll start with the basics. In four full time seasons in the majors, he's put up the following OPS numbers (vRHP/vLHP/overall):

.793/.967/.837
.846/1.072/.899
.713/.795/.740
.557/.893/.689

Progression: 
vRHP .793--.846--.713--.557
vLHP .967--1.072--.795--.893

Worth noting, of course, is that Hall's OPS was and is mostly driven by slugging. Overall slash lines in those four years:

.291  .342  .495
.270  .345  .553
.254  .315  .425
.225  .293  .396

It looks to me like his BA-OBP gap has stayed pretty consistent. Going back now to the minors, here's Hall's (OBP-BA) gap, showing his plate discipline:

.027
.036
.039
.051
.038
.051
.075
.061
.068

Not what I expected to see at all. He went from a hacker in the minors to a patient hitter in the majors, and he remains patient. The average has been the problem. Unfortunately, there's no batted ball data for the minors, but we have fangraphs and a four full-season sample to find some trends.

via www.fangraphs.com

The spike in flyballs in '06, coupled with a career high HR/FB rate of 20% (around 13% every other year in his career), explains the 35 homer outburst. I don't expect him to come close to that again. What's interesting is the line drive numbers--the career high in '05 makes sense given his also career high average of .290, but they actually fell in '06 and rebounded in '07, followed by another fall--without the fly ball numbers-- in '08. That leads to BABIP:

via www.fangraphs.com

A casual analysis might determine that Hall was unlucky this year due to the low BABIP, but given the decrease in line drives and fly balls and increase of ground balls, the BABIP isn't too out of line. So has something changed in his approach at the plate, making the average fall?

His walk and strikeout rates have stayed almost exactly the same since '05, with the only exception a career-best walk rate in '06. He Ks more than the average player, but his strikeout rate didn't jump too much last year.

Pitchers haven't drastically changed their approach against Hall, either, and there is only one thing that really stands out to me in his plate discipline: he's swinging at more pitches outside the zone and actually making contact with a higher percentage of these pitches outside the zone. I'm theorizing here, but I'd think that would lead to more weak groundballs and fewer line drives. I remember seeing the same problem with J.J. Hardy in a fanpost before he went on his hot streak this year:

I was surprised to see Hardy here. His LD % is pretty worrisome. His groundball percent is at a career high and line drives are at a career low. Remember in spring training when he said he wanted to shorten up and use his two strike approach more? Well, he's striking out less and hitting more balls weakly.

Hall seems to have adopted the "2 strike approach", hitting more balls less hard and seeing a resulting dip in line drives and BABIP. J.J.'s problem might have been a small sample result, but Billy has been doing this for 2 years now. We can also speculate how his eyesight has affected his hitting ability, but his contact rate hasn't really gone down too much in any other area.  

He'd certainly be worth a gamble for a shortstop-needy, big budget team that can afford to hope he has a .700ish OPS year playing full time. I'd be willing to bet his .500 range OPS vRHP won't happen again, as he's never been below .700 vRHP before in his career. High .600s- low .700s is possible. And there's no doubt he's a heck of an option in the righty side of a 3B platoon. 

A team like the Brewers, if they expect to contend, shouldn't play Hall every day at third base, but that doesn't mean he couldn't play everyday somewhere. It's relatively easy to find a lefty platoon 3B (Branyan!) for cheap and it would be foolish to hope for a .700 OPS vRHP from Billy when Branyan can contribute .800.

So I'm going to vote for a combination of numbers 1 and 2 above-- I think something in his approach/game changed, even if it wasn't a concious change, and there is some evidence that his 05-06 success wasn't sustainable anyway- '05 had a pretty high BABIP-driven average and '06 had the ridiculous HR/FB ratio.

If he played a full year at this point, I'd expect about .260/.315/.400 with about 15 homers. You can do worse at shortstop, but I don't think he's a good 3B anymore. Or an MVP candidate, Ned.