A major complaint we've seen over Ian Stewart the past 2 seasons is that we're not sure that Stewart would be ready to take over the role of starting 3B. Colorado has never really been short of solid 3B production, as we've had Vinny Castilla, Garrett Atkins, and even got solid production from guys like Jeff Cirillo.
When Colorado finally cut ties with the declining Atkins after the 2009 season, the obvious incumbent to the position was Stewart. What we saw from Stewart prior to 2010 was an obvious power threat (career .208 ISOP) and excellent eye (.090 ISOD), but a lot of trouble putting the whole package together in terms of fueling that OPS with a decent batting average (.242/.332/.450 career line - partially deflated by 46 awful PA in 2007).
The complaints against Stewart, despite being a low-average hitter, were obviously the sheer number of punchouts. 2008, Stewart struck out 35.3% of the time. That was good for 4th in the majors among players with 300+PA, behind Jack Cust (41%), Mark Reynolds (37.8%), and Kelly Shoppach (37.8%). 2009 wasn't MUCH better, but the K% did drop to 32.5%, good for 10th in the majors.
In this area, Stewart HAS improved his game, dropping that punchout rate to 29.7%, still 10th in the majors, but that high number of strikeouts will remain problematic for his career. The hope for Stewart is that he can try and brush his punchouts under the rug in a Mark Reynolds fashion by walking a lot (which he does) and hitting for berserk power (which he might yet really prove to us). We're still waiting on that power to really kick in, because out of the top-10 in K%, Stewart's .184 ISO ranks 9th, just ahead of Cincinnati's Drew Stubbs' .182.
But there are subtle differences in Stewart's 2010 season as compared to his 2008 and 2009 campaigns. In 2008, Stewart's MO was "SWINGSWINGSWINGSWING" - swinging at 47.8% of pitches while only making contact with 71.3% of those balls he swung at. His 13.4% Swinging Strike percentage wasn't too great either. 2009, his strategy changed to "TAKETAKETAKETAKE", and we saw those numbers change to 42.2% swung at, 71.9% contact (so I guess we can say "selective"?), and 11.5% swinging strikes.
We can look more into the changes Stewart is making past the jump.
So from 2008 to 2009, Stewart swung at fewer pitches (including a 7% drop on swinging at pitches outside of the zone and a 6% drop on swinging at pitches INSIDE the zone) with roughly no change in overall contact, which resulted in fewer swinging strikes, fewer strikeouts, more walks, and more Power. The downside of this is that he also batted for a low BABIP (.270) and we saw his LD% drop from 25% to 14%, his GB% jump from 31% to 40%, and his wRC+ drop from 105 to 98.
If all those numbers made you want to stab your eyes out, we could probably summarize the change from 2008-2009 as "Change from free-swinger to a more timid swinger who gets too far behind in the count and ends up punching out or grounding out anyhow". While he DID park 25 longballs, many pitchers would basically just get him to sit on stuff he didn't like and then have him at their mercy.
So moving on to 2010, we see the following slash line: .252/.344/.436, good for a .780 OPS, .340 wOBA, and 104 wRC+ (and remember wRC+ is park adjusted and all that good stuff). He's only punched 12 longballs thus far, but there's hope yet.
As far as changes in his swing, 2010 is kind of funny.
2008 was SWINGSWING and 2009 was TAKETAKE. 2010 seems to be back to SWINGSWING (45.0% - lower than 2008, higher than 2009), but with a bit of a catch. His swinging-strike% had stayed the same as last year (technically dropped by .4% - he's at 11.1% - I'm not writing home about that) but his contact rate has jumped from a mid-to-upper 71% to 74.1% this season. He needs 6 singles to match his 2009 total (50) and only 30 hits overall to match 2009 (97).
Now I'll be honest with you, even while writing this, I'm having to do a bit of convincing myself to get on board with Stewart. The concern is that he won't ever be better than a .260 batter (and still, if he's posting a .260/.350/.450 line, I'll find other things to complain about) and he'll be too extreme of an OPS hitter rather than improving the components.
Well, there's a few things to take into consideration before we completely give up.
First, he's only 25. We've been using age excuses for a while now, but it's still a fact that not everybody "gets" it at the same age or service time as others. Add in the fact that whenever he'd hit a spell of struggling, he'd be benched for Garrett Atkins, and there's some trouble adjusting. Through age 24, Stewart compares favorably with: Gary Gaetti (meh), Mark Reynolds (ok), and Mike Schmidt (awesometastic). I'm not going to pretend that I think Stewart is going to blossom into a top-5 all-time 3B, but it's worth mention that Mike Schmidt struck out an awful lot over his career (averaged 127K per season), but he also complemented it with an awful lot of walks (averaged 102BB per season).
Second thing worth mentioning is that Stewart's OBP-heavy .737 OPS at Coors Field doesn't quite stack up to his SLG-heavy .830 OPS on the road. Crazy, I know. Something just isn't giving when Stewie bats at Coors right now, but that seems like a prime split for a power hitter to improve upon.
Third thing to make note of is how strongly Stewart has come on as of late. After muddling through a 87 wRC+ May and absolutely slogging his way through a 54 wRC+ June, Stewart has batted .281/.410/.656 in July, good for a 1.067 OPS, .452 wOBA, and a 177 wRC+. Yes, I'm aware that 39PA isn't exactly the best sample to base an evaluation on, but it's what we have to work with right now, and watching him belt 27% line drives while punching out only 18.8% of the time makes me a happy camper.
Essentially, if Stewart can keep up anything even close to his July performance the rest of the way toward October, we could be in very good shape at 3B. On the flipside, we could also be cruising for the proverbial bruising.
So moving forward, what we need from Ian Stewart is as follows: Continue playing good defense (the fielding metrics are a bit sketchy on him, but it's not to the point of being problematic), continue hitting right-handed pitching (105 wRC+ v R/93 wRC+ v L) and figure out a way to start hitting at Coors. Given what we've seen of him so far this season, he's doing some things right. He needs to continue with the good peripherals (ISO's, Swing%/Contact%) and continue refining his game (BB% up, K% down).
I'm not going to pretend that he's amazing and is saving the team or whatever. I'm not touting him as the most amazing player and he's going to storm the gates of October and win us the trophy. But what we can say about him is that he's roughly right in the middle of the pack when it comes to qualifying 3B. No, he's nowhere near Zimmerman or Longoria level. But for the time being, it's good enough. I know we've had to be satisfied with "good enough" for a large portion of this season, but look where we are: 9 games up on .500 and slowly gaining momentum. Much like Stewart.
We've been saying all season that "As Troy Tulowitzki goes so go the Rockies", but I'd wager that as the Rockies pick up speed, you can be sure we'll see Stewart right in the middle of things.