Remember when it was reasonable to debate whether Zack CozartÃ¢â‚¬â„¢s offense was so poor that the Reds couldnÃ¢â‚¬â„¢t afford to keep him in their lineup? He was a poor offensive player in 2012 and 2013, but his 55 wRC+ was the worst among qualified players in 2014. Basically, he may have been the worst offensive player in baseball that season. And he drove me crazy, but no one seemed to care about that.

Fast forward to the present, and Cozart doesnÃ¢â‚¬â„¢t even resemble that player. The guy who never hit .255 over an entire season has been over .300 for most of the year. His career high OBP was .288 in 2012 but currently stands at .332. The biggest difference in results, though, comes from CozartÃ¢â‚¬â„¢s considerable uptick in power. In CozartÃ¢â‚¬â„¢s first three seasons, he never slugged better than .399. Right now, heÃ¢â‚¬â„¢s slugging .532 and may represent the Reds in the All Star game.

His impressive play puts the Reds in a difficult situation: should they trade him or try to sign him to a reasonable extension? This predicament resembles the Jay Bruce issue except that Bruce had a longer track record of success before struggling the last two years. But for over 400 plate appearances between 2015 and 2016, Cozart has hit like a top five to seven shortstop in all of baseball.

CozartÃ¢â‚¬â„¢s vast improvement began with watching video. After his disaster of a season in 2014, Cozart took to the film room and apparently found a mechanical error in his swing. He made the appropriate changes and last season slugged .459 while posting a 104 wRC+ in 214 plate appearances. Before we could see whether Cozart could sustain his hot start, he suffered a knee injury that required season-ending surgery.

I certainly didnÃ¢â‚¬â„¢t think Cozart would pick up where he left off after rehabbing a shredded knee. But heÃ¢â‚¬â„¢s been even better. Is this real? Has Cozart really become a top three shortstop in the National League? The underlying numbers may help answer this question and give us some clue as to whether the Reds should sell high or buy in for more.

First, here is a table comparing CozartÃ¢â‚¬â„¢s batted ball data from his first three full seasons with his last two (2015-2016).

Cozart’s success has largely come from been hitting the ball harder. That jives well with the eye test. In fact, in 2016, he has a Hard% of 33.3%, much higher than his career mark (24.6%). Hitting the ball harder is obviously better than the alternative, but the other numbers are promising as well. Groundballs are the worst batted ball type because they rarely go for hits, let alone extra-base hits. They have become even less productive since teams started shifting drastically.

Cozart has decreased his GB%Ã‚Â significantly while increasing both his LD% and FB%. Batters typically hit between .650 and .700 on line drives, and CozartÃ¢â‚¬â„¢s LD% is over 24% in 2016, likely contributing to both an elevated BABIP (.306) and his impressive batting average. As we will see shortly, he needs to hit for a high average to get on base at a reasonable clip.

Another large change between CozartÃ¢â‚¬â„¢s poor offensive seasons and the last 400+ plate appearances is that he has doubled his rate of homeruns per fly ball. Ã‚Â After hitting only four homeruns in 2014, he was on pace for around 30 homeruns in 2015 before his injury. He is on a similar pace now. Last season, Brandon Crawford led all shortstops with 21 homeruns, so if Cozart hits between 25-30, he will be in elite company.

Players who see this kind of production increase have often improved their plate discipline. In CozartÃ¢â‚¬â„¢s case, his swing and contact rates have remained incredibly stable over his career, and he does not walk much at all, meaning all of his on base ability comes from his batting average. Ã‚Â However, Cozart has cut down his strikeout rate in every season from a career high 18.8% in 2012 to a solid 12.9% currently.

The numbers suggest that Cozart may have indeed fixed some type of mechanical error. For 416 plate appearances, he has hit more lines drive and the ball harder in general, greatly increased his power, and struck out less. Those factors indicate an improved player.

Even if Cozart regresses to a roughly average player, a pretty steep decline from where he is currently, his defense makes him an above-average player at the least. It made sense to question whether Cozart could return to his defensive wizardry after major knee surgery, but he has shown no ill effects thus far.

All of this Cozart goodness combines for the third most WAR among shortstops in the National League (1.8). A top three shortstop is a good thing to have, but of course, there are other factors to consider when deciding whether to trade or extend him.

Cozart turns 31 in August, traditionally an age when players, especially middle infielders start to really decline. The Reds have control of him through the 2017 season, so an extension may not kick in until 2018 when he will turn 33. ThatÃ¢â‚¬â„¢s a dangerous extension.

The decision really hinges on when you think the Reds can compete and whether you believe that either Jose Peraza or Eugenio Suarez + the prospects from a Cozart trade outweigh the production Cozart will give over the next 3-5 seasons.

While Suarez has struggled at third base, he showed some potential at shortstop before being moved, and frankly, while I believe in the bat to a certain extent, he hasnÃ¢â‚¬â„¢t exactly proven he can have prolonged success at this level.

He currently own a career 97 wRC+ with a .258/.310/.416 slash line in roughly 900 Major League plate appearances. He turns 25 in July, so he has some time to figure things out.

If Suarez could play close to average defensively at the position, the bat likely plays. I understand that he has often impersonated Pele at third this year, but struggling at third doesnÃ¢â‚¬â„¢t necessarily mean he would be a bad shortstop. Range has not been his issue. Still, Suarez does not inspire much confidence on defense right now.

Peraza has started most of his games in AAA this season at shortstop, which would seem to portend his role in the Major Leagues. Scouts think he would be excellent at second but that he has potential to handle shortstop as well. As far as his hitting ability, he has zero power, but Baseball Prospectus does have this to say:

His feel for the barrel is outstanding, and he consistently makes hard contact thanks to his hand-eye coordination and a compact, quick stroke. The hit tool could be plus if took more pitches and worked more counts, but he doesnÃ¢â‚¬â„¢t, so it isnÃ¢â‚¬â„¢t.

PerazaÃ¢â‚¬â„¢s .301/.340/.386 slash line in the minor leagues fits this description to a tee. He may hit for an excellent average, but he doesnÃ¢â‚¬â„¢t have elite on base skills and possesses almost no power. He does have outstanding speed that could boost his value if he can manage to get on base enough.

So encouraging. Or discouraging. I canÃ¢â‚¬â„¢t decide. The reality is that Peraza has a regular job waiting on him somewhere, and it will likely happen in the near future. Because Phillips isnÃ¢â‚¬â„¢t going anywhere, and Billy Hamilton has suddenly figured out what a bat is used for, shortstop would seem to be the place for Peraza.

Trading Cozart now is likely selling high and would bring a pretty good prospect or two in return. Not elite prospects but something useful for a rebuilding club. An extension of three years or so probably wouldnÃ¢â‚¬â„¢t break the bank, and the Reds may get an above-average player or better. These are the tough decisions that rebuilding clubs need to make. Hopefully, the Reds choose wisely.