Last week the mere notion of the Browns finding a trading partner for Colt McCoy made me chuckle with great delight. Why would any team give up anything of any significance for a quarterback who will be released soon anyway, and he’s not worthy of a trade investment? Even a seventh-round pick seemed like far too much.

But in those moments when I wrote those words, I neglected the 49ers. Yes, the 49ers, the defending NFC champions who fell only a few points shy of winning this year’s Super Bowl. They’re in need of a backup they can trust after Alex Smith was traded to the Kansas City Chiefs. They also have 14 picks in this month’s draft, and 14 rookies starting for a team that just played in the Super Bowl is a thing that definitely wasn’t happening.

And that, friends, is why Colt McCoy is the newest 49er.

Before we continue much further, let’s start a slow clap for the Browns here, a franchise that’s seldom worthy of such fanfare. Jason La Canfora was the first to report that McCoy will now be Kaepernick’s backup, and in exchange the Browns will get a late-round pick. Again, any pick — or rather, anything at all — is more than McCoy was worth.

But that doesn’t mean the Niners screwed up here. Their abundance of picks provided freedom to chase any need they desired to fill, and with backup quarterback-types and very borderline starters quickly flying off the market (Ryan Fitzpatrick, Kevin Kolb, Matt Flynn, Carson Palmer), San Fran needed to act quickly, and they couldn’t let McCoy become available to the rest of the league if they had determined he was the right fit behind Colin Kaepernick.

Sure, fine. The next question, though, is why spend on McCoy, instead of just signing Matt Leinart, Tyler Thigpen, or Brady Quinn? All three of those names have starting experience, and they’re equal to McCoy in terms of their awfulness. Best of all, they would have been free, or at least free in the sense that no trade fee is required for their crappy services.

The best and only explanation is that while McCoy’s legs will never move at the same rate as Kaepernick’s, he’s easily the most mobile of the remaining quarterbacks available either through free agency or a trade. If any sort of spot start duty is needed from McCoy, some faint element of the read-option can remain, and he’ll be isolated by the 49ers’ strong rushing game. In 24 career game appearances, McCoy has 363 rushing yards.

Maybe “mobility” is a term applied far too liberally there. McCoy is…athletic? You get it, surely. McCoy isn’t nearly as statuesque as the remaining free agents at quarterback, and since short passing was his game in Pat Shurmur’s west coast offense, he’ll be asked to play backyard kiddie catch with Vernon Davis and Michael Crabtree. So you see, Colt McCoy really does still serve a purpose.