A voter's 2012 NL Rookie of the Year ballot

Bryce Harper's strong debut season helped the Nationals finish with the best record in baseball. Jonathan Newton/The Washington Post/Getty Images

As one of the few entrusted with a National League Rookie of the Year vote this year, there wasn’t really that much drama to making a selection, at least not for me. After September, it was clear that Bryce Harper should win, and that’s who I put atop my ballot.

Of course, Harper made it easy for me, capping his already incredible introduction to the majors with a tremendous final month, hitting .330 AVG/.400 OBP/.643 SLG (with 18 extra-base hits) in September. If the season had run just five months, the choice between Harper, D-backs lefty Wade Miley and Reds cornerman Todd Frazier would have been much, much more difficult.

As of the last day of August, Harper was at .254/.324/.432 -- respectable for a teenager pushed into a pennant race, but not exactly eye-popping. At that same point, Frazier was hitting .293/.352/.549, and Miley was 14-9 with a 2.85 ERA and 14 quality starts (using runs, not scorer’s opinions) in 23 turns. If the race was between anybody, it looked like it would be between those two, with Harper holding the bronze. But Miley had a mediocre September (posting a 5.40 ERA in six starts), while Frazier imploded, hitting just .176/.235/.257. After all Frazier had done to help carry the Reds to the top of the division, it was a shabby way to end an otherwise superb season. Frazier also played a much better third base than he got credit for, which mattered to me in the end for reasons I’ll get into later.

Now, admittedly, the trophy is supposed to be Rookie of the Year, not rookie of the month of September, but making a judgment based on their performances over the full spread of the season made it easy for me to select Harper over Miley (who I put second) and Frazier.

Harper’s sizzling finale also cinched what’s already an annual temptation when it comes to picking the Rookie of the Year Award, which is favoring the guy you think has a better future ahead of him. That’s very much what you are not supposed to do when voting for Rookie of the Year, though, which I suppose helps go a little toward explaining why history and the voters have given us some pretty lamentable selections. Todd Hollandsworth, anyone?*

The only difficulty I had was with the expectation that you have to vote on the performance within the season in question. Reviewing rookies, it’s hard not to vote for the guy you’re most excited about. Follow a guy through his touted rise through the minors and then see him deliver on the promise you’ve been anticipating, and it’s hard not to get jazzed by that, as a fan or an analyst.

Which is why I had to spend some time thinking about my third-place vote more than the top of the ballot. Not that Frazier won’t have a nice career, but I was tempted to recognize the rookie who was perhaps the most flat-out impressive to watch play, and a guy who figures to be an impact player on offense and defense for years to come: Atlanta shortstop Andrelton Simmons.

Because of injury, Simmons played only a third of the season, so there really wasn’t much of a case to make. I looked back at Willie McCovey winning the award in 1959 as a precedent for touting a player with so little actual playing time. McCovey played in 52 games for the Giants, notching 219 at-bats but a 3.0 WAR; he was the unanimous selection. Simmons was worth 2.8 WAR in his 49 games for the Braves, so I coulda, I mighta and perhaps I shoulda given him a third-place token vote. Maybe it’s a visceral thing, watching him play defense, because it feels like he might be for the Braves what Elvis Andrus is for the Rangers.

It’s hard to believe Simmons might have generated 54 defensive runs saved over a full season, as Baseball Info Solutions suggests. That’s one less than what full-season leaders Brendan Ryan of the Mariners (28) and Darwin Barney of the Cubs (27) cranked out combined, so it’s sort of hard to take seriously. But it does suggest Simmons is going to be one of the biggest impact players on defense for years to come. Add in a much better bat than expected, and he’s somebody you won’t forget.

In the end, I couldn’t overlook Frazier’s full season -- including his own fine glove work at third base. As much as I wanted to vote for Simmons, I gave Frazier my third-place vote. But 10 or 15 years from now, we’ll be talking about Simmons in contrast to Harper when we debate who's the biggest star from the NL’s rookie class of 2012.

*OK, not even that excuses Hollandsworth, still one of the most lamentable selections for any award ever; he had no business beating Edgar Renteria or Jason Kendall. The horror, the horror.

Christina Kahrl covers baseball for ESPN.com. You can follow her on Twitter.