Here's how Brandon Belt's comparable players aged

Brandon Belt has a long-term contract with the Giants. It still feels funny to type. That means the only young player under 30 on the team who won't be around until at least 2020 is ... Cory Gearrin? Let's start the talks up, Bobby. Lock up everyone.

Belt responded to his new extension by almost hitting a dinger off Clayton Kershaw, then pummelling a ball to dead-center to help spur the Giants' unlikely comeback on Sunday. He's also walked six times already this season, when he didn't have his sixth walk of the 2014 season until his 108th plate appearance and 25th game. If this is the Belt we're going to get this season, this contract will be a steal.

However, what if Belt doesn't improve at all? What if the only thing he does differently is stay healthy? It's time to find some comparable players in baseball history and see how they aged. We can adjust our expectations upward or downward based on how Belt finishes the season, but this will give us an idea.

(An aside: Two of the best possible comps for Belt statistically are Leon Durham and Willie Mays Aikens, both of whom had their careers cut short because of substance abuse. That just breaks my heart, and I'm not sure what to do with that information other than share it here.)

Some housekeeping, first. The similarity scores at Baseball-Reference don't help us much with Belt because they're based on raw numbers, which don't account for a) AT&T Park, b) the lower offensive levels that Belt has dealt with for much of his career, and c) the stupid injuries that follow him around like a dark cloud. So I'll look for players who were all of the following:

1. A left-handed hitting first baseman
2. who had a little power, but not a ton
3. who took a fair amount of walks
4. who wasn't a total slug on the bases

Belt's career adjusted OPS is 126. Let's see who ticked off those boxes up there and had an OPS+ close to that.

Hal Morris

You were looking for an exciting name among the comparable players? Willie Stargell, maybe? No, sorry. For as much as I love Brandon Belt, he's definitely more Hal Morris than Willie Stargell.

That's not a bad thing, though. Morris was more of a late-bloomer than Belt, not getting his first full-time gig until he was 25, but he had a similar combination of gap power and athleticism. Through his age-27 season, he had a 122 OPS+ for his career, even if that was more average-dependent and less saturated with dingers.

Here's how he looked at the same ages covered by the Belt extension:

• Age 28, 112 OPS+
• Age 29, 128 OPS+
• Age 30, 106 OPS+
• Age 31, 124 OPS+
• Age 32, 77 OPS+
• Age 33, 90 OPS+

Three perfectly fine seasons, with a cliff at the end. I'm not going to say that would be a great scenario, but it could be worse. If the Giants get a solid four seasons out of the six-year contract, they'll have done well, as far as long-term deals go.

(We're not going to worry about WAR, in case you were wondering, because not all of these players have the same defensive profile or injury histories. Just focus on the rate stats.)

Wally Joyner

Joyner was a more-hyped prospect, even with Belt getting plenty of hype on his own, and he had far lower strikeout numbers than Belt ever had. The rest of the numbers look eerily similar, though, right down to that little wisp of unexpected speed. His career OPS+ was 122 through his age-27 season, which was quite similar to Belt.

Here's how he looked at the same ages covered by the Belt extension:

• Age 28, 111 OPS+
• Age 29, 134 OPS+
• Age 30, 101 OPS+
• Age 31, 120 OPS+
• Age 32, 113 OPS+
• Age 33, 118 OPS+

Then he stuck around for three more fine seasons, just for good measure. This is kind of what I'm predicting for Belt, with an excellent season coming right before a standard Belt Wars season, but generally pretty steady. The Giants would be just fine with a Wally Joyner career path.

Lyle Overbay

Overbay was also a late-bloomer, but that's more because the Diamondbacks had no place to put him. They were already stumped with where to put Erubiel Durazo, so they let Overbay languish in the minors for a while.

When he was in the lineup, though, he hit, with a 122 OPS in his age-27 season, his first full season as a starter. Here are his numbers at the same ages Belt will be under the extension:

• Age 28, 113 OPS+
• Age 29, 125 OPS+
• Age 30, 85 OPS+
• Age 31, 109 OPS+
• Age 32, 119 OPS+
• Age 33, 105 OPS+

He was worth at least a win in all of those seasons, topping out at 3.2 WAR. That seems disappointing, but that's almost exactly the kind of performance the Giants would be paying Belt for. He's not getting All-Star money, not quite. An Overbay career path would suit them better than you might think.

Dan Driessen

The former Giant had a good defensive reputation, sound wheels, and a 18-homer bat, and he also toed that line between .250 and .300, just like Belt. He got his start much younger than the other players on this list, and his OPS+ through age 27 was 112, so while he's not the best possible comp, he's still a pretty danged good one.

The Belt contract for him would have been fine:

• Age 28, 121 OPS+
• Age 29, 107 OPS+
• Age 30, 119 OPS+
• Age 31, 122 OPS+
• Age 32, 126 OPS+
• Age 33, 90 OPS+

That last one was with the 1985 Giants, of course, because that's how that team rolled. But for five years out of six, Driessen was an asset at the plate. His WAR were ugly because of low defensive marks, but would this Baseball-Reference sponsor lie?

Dan Driessen was one of the best defensive first basemen in MLB history. Dan Driessen's career fielding percentage at first base (.995) is better than that of ANY first baseman in the National Hall of Fame!

No way. Fielding percentage don't lie.

Cecil Cooper

Cooper was more of a hacker when he was younger than Belt, but he's included because the adjusted OPS marks were similar through his age-27 season, and because he got really, really good and I wanted to cherry-pick.

• Age 28, 133 OPS+
• Age 29, 133 OPS+
• Age 30, 155 OPS+
• Age 31, 151 OPS+
• Age 32, 142 OPS+
• Age 33, 138 OPS+

Wheeeeee! That would be a barrel of slumpy-shouldered monkeys, and we would love every second. This isn't a perfect comp, but it's better than you might think, and they both look pretty badass with beards.

Jason Giambi

Giambi's OPS+ through age 27 was 128, just two points higher than Belt's. Then his career absolutely took off for no apparent reason. This is probably going to happen with Belt, imo.

Rafael Palmeiro

Palmeiro's OPS+ through age 27 was 130, just four points higher than Belt's. Then his career absolutely took off for no apparent reason. This is probably going to happen with Belt, imo.

Kent Hrbek

Wait, wait, wait, back to those last two. I mean, I'm in no position to suggest ... it's just that ... I mean if he were just a little curious, I wouldn't ... I ... no, never mind, forget I said anything, this has gone off the rails, I can't apologize enough, move on.

Kent Hrbek

Hrbek had more power, but he also played in the Homerdome. If you use my favorite toy at Baseball-Reference, he looks extraordinarily Belt-y.

Here he is during the theoretical Belt-extension years:

• Age 28, 150 OPS+
• Age 29, 139 OPS+
• Age 30, 131 OPS+
• Age 31, 125 OPS+
• Age 32, 113 OPS+
• Age 33, 120 OPS+

Quite nice, with a calm, steady decline. Of course the Giants would be thrilled with this.

There were bummer comparisons, but there weren't a lot that made you think of Belt immediately. Nick Johnson came up, but his health problems weren't related to random hit-by-pitches. Justin Morneau also came up ... and, okay, that one makes you think of Belt, so we'll just move on. You can dig through my original search, if you want. It's a fun bunch of names.

For the most part, though, it's a lot easier to find success stories with Belt's profile than it is to find cautionary tales. Belt doesn't have to be an MVP to make this contract look smart. He doesn't even have to be an All-Star. If he's the same ol' Belt, everything would be just fine.

If he wanted to mimic the Cecil Cooper path, though, I'd be okay with that. Cross your fingers, everyone.