It's not fair, but the thing most everyone will remember about the first week of real stress-testing for the new MLB replay rules will be San Francisco getting screwed. It happened Tuesday evening as the Giants visited the Diamondbacks in Arizona. With two outs in the bottom of the fourth, San Francisco starter Matt Cain attempted to pick Arizona centerfielder A.J. Pollock off at first base. Pollock was called safe, but manager Bruce Bochy challenged the call -- and on review, the umpires in the MLB "war room" or "command center" (or whatever silly term you want to use to sex up a room full of computer monitors) agreed with the umpires on the field. They were arguably wrong in that determination, but the play was extremely close.

What was not extremely close, however, was what happened a few batters later with Pollock now on third base thanks to a Gerardo Parra double. On a passed ball by catcher Buster Posey, Pollock came home -- and was clearly thrown out at the plate, with Cain applying the tag on his heel as Pollock slid. It's hard to believe how home plate umpire Eric Cooper got this call wrong to begin with, considering the ball beat Pollock to the plate by a good two seconds and when the Arizona centerfielder finally got there, he found Matt Cain basically draped across the plate waiting for him. But Cooper did get it wrong, and the Giants were unable to challenge (since they had used up their challenge on the pickoff throw), and the run counted.

This was the worst-case scenario for a challenge-based replay system. All of the above happened so early in the game that the umpires were forbidden to exercise their own discretion in reviewing the call -- and then that run provided the margin of victory in the game. It was just like what would have happened last year if the umpires had blown two calls in one inning in spectacular fashion, except it took ten minutes longer.

But it's probably a good thing this happened so early in the season. Baseball could probably use one or two more worst-case scenarios, just to make sure MLB's head office doesn't forget that they're possible. While instant replay's detractors will use situations like the one in Arizona on Tuesday as blanket arguments against the entire concept of replay, those people are fighting a losing battle -- instant replay isn't going away. Once that particular box has been opened, it's not being closed again. What situations like these are a great argument against, however, is a particularly boneheaded challenge system that prioritizes giving major league managers more buttons to press and levers to pull over getting calls right.

Imagine that instead of a manager challenge, Eric Cooper just has an earpiece that's hooked up to the war room/command center/ump cave in New York's Chelsea Market, where Major League Baseball Advanced Media resides. Maybe Bruce Bochy still comes out to ask for a review of the first Pollock incident -- the pickoff at first -- and maybe he doesn't. If he does, maybe the umpires indulge him; maybe they don't. All else being equal, they probably don't -- a bang-bang pickoff play is not, to an impartial observer, particularly worth stopping the game over.

But the play at the plate? The scoring play that Matt Cain spent almost a minute pleading with Cooper about while visibly restraining himself from using four-letter words? The play Bochy then came out and spent more time begging the umpire to look at again? The play Cooper got clearly and obviously wrong? That play gets reviewed by an impartial observer every time, and it gets fixed by said impartial observer every time, because it is very much not a bang-bang play. If umpires, not managers, had review control from the very first pitch, not only does the call at home plate get fixed, but the review at first base likely never happens -- and that means not only do the umpires get the important call fixed, but the game spends less time in limbo as a consequence.

That's what replay should be there for, ideally: fixing the big mistakes and not sweating the small stuff. The current system almost inverts those priorities. Since managers can't see the future, most may use the challenge as soon as a situation pops up where it looks like a call might be reversed in their team's favor -- no matter how big or small the marginal gain is. After all, if they get the call on the field reversed, they get their challenge back, and the plays open to review are such simple binary rulings on fact, not umpire judgment, that most challenges should be successful.

For now, the Giants have probably learned an important lesson about the current system that many teams around the league would do well to heed: a manager should never challenge a play he wouldn't be willing to go out and argue about on the field. San Francisco got caught trying to pick up an out in a situation that in early April wouldn't have merited more than maybe some dugout jawing at the first base ump, and they did so very early in the ballgame. As long as this is the system MLB is using, it's incumbent on the teams to recognize how best to use it.

For the long term, all this does is highlight that the current implementation of instant replay is, in fact, a resource optimization mini-game -- and that has no place in a system that's supposed to prioritize getting the call right first and foremost. In order for that implementation to change, though, a couple other teams are going to have to get the short end of the stick the same way the Giants did. And you know what? I'm okay with that. The sooner the shortcomings of the challenge system are made self-evident, the sooner it can be done away with, and teams that lose because of it would have lost those games without replay anyhow.

If in a couple months, situations like the Giants' 5-4 loss to the Diamondbacks are the only thing people remember about the first struggling steps of full instant replay in baseball, that's a good thing -- because that means MLB's first tentative steps into modernized officiating have gone off smoothly. And we'll have all the evidence we need that in the offseason, the challenge system needs to go.