Robinson Cano: Future Hall of Famer, but perhaps no longer superstar

It wasn't the best of times for Robinson Cano in 2015. The Seattle Mariners' second baseman struggled during the first half of the season, hitting .238 through the end of June with only four home runs. His team, a popular preseason pick to make the playoffs, stumbled as well, with a 34-40 record. Later in the season, Cano disclosed that a stomach illness he had contracted in 2014 had left him with a bad case of acid reflux that affected his sleep and energy level. Maybe that also explained some of his baserunning lapses and defensive mistakes.

In November, Mariners first-base coach Andy Van Slyke -- who had been fired along with manager Lloyd McClendon and most of the coaching staff shortly after the season ended -- questioned Cano's work ethic in a radio interview with a St. Louis station, and blamed Cano for, well, just about everything:

"Robinson Cano was the single worst third-place, everyday player I've ever seen -- I've ever seen for the first half of a baseball season. He couldn't drive home Miss Daisy if he tried. He couldn't get a hit when it mattered. He played the worst defense I've ever seen at second base. I mean, I'm talking about the worst defensive second baseman ever -- I've ever seen in 20 years in the big leagues. He couldn't catch the ball. No, I take that back. Any ball that was hit to him was an out. Any ball that he had a chance to turn a double play, he's still maybe the best in the game today. He's got a great arm. But I'm telling you ... Robinson Cano cost the GM his job. The hitting coach got fired because of Cano. And the manager and the coaches got fired because of Cano. That's how much impact he has on the organization. He was the worst player and it cost people their jobs in the process."

Don't hold back, Andy.

There's more. Cano hit .330/.383/.536 for the final three months with 55 RBIs in 82 games, still not enough to drag the Mariners over .500 or save Van Slyke's job. He did that while playing through two sports hernias that required surgery after the season. Then came a New York Daily News report in which a "long-time friend" said Cano wasn't happy in Seattle and would love to find a way back to New York.

Cano, of course, is still with the Mariners and we're left with this question: Is the 33-year-old future Hall of Famer still a superstar player? He's ranked No. 49 on our BBTN100 list -- ahead of players who clearly had better seasons in 2015, such as teammate Nelson Cruz, Mookie Betts, A.J. Pollock and Yoenis Cespedes -- but it's a huge drop from his No. 8 overall ranking last year.

If there's a reason to believe that Cano's stomach illness did affect his first-half performance, these two heat maps offer strong supporting evidence. The top map is his batting average against fastballs through June 30 and the bottom one is his average against fastballs from July 1 on:

They show two different players. Cano hit .255/.298/.331 in those first 75 games and then .392/.445/.671 in his final 82 games. Again, this is just against fastballs, but that's the most basic of hitting skills. Older players often struggle against fastballs as their bat speed declines. Perhaps Cano's health issues prevented him from turning on pitches, or slowed his bat.

Of course, Cano also started slowly in 2014, his first season with the Mariners -- at least in the power department, when he hit just four home runs in his first 77 games before finishing with 14. Is it possible that he has started slow both seasons because of his age, and that -- at least in 2014 and 2015 -- he has been able to make adjustments in the second half?

ESPN Insider contributor Tony Blengino might agree with that assessment. In a series of reports for FanGraphs that looked at batted ball authority, he wrote of Cano:

As you can see, there's still a lot to like about the Mariner second sacker: he hits the ball harder in the air than any of his AL positional peers, and like Kipnis, routinely runs liner rates well above league average. There are clear signs of decline, however. His K rate is trending up, his walk rate is down, he cannot elevate the baseball with any regularity, and his BIP authority, while still good, isn't what it used to be. His floor remains high, but his ceiling is nowhere near where it once was. 2015 is his new normal.

Cano's strikeout rate was a career-high 15.9 percent in 2015, although he did improve in this regard as well in the second half, dropping from 17.3 percent to 14.1 percent, and his K rate in 2014 was actually the second-lowest of his career. His strikeout-to-walk ratio improved from 64/17 to 43/26. Those indicators all seem like positive news for Mariners fans.

There is this, however: Cano was once one of the best in the game in punishing off-speed stuff (curveballs, sliders, changeups, splitters). He hasn't been nearly as effective with the Mariners:

Like his production against fastballs, Cano did improve -- from a .541 OPS through June 30 to .740 afterward -- but that trend line backs up Blengino's analysis, that Cano is in decline. I'm guessing a lot of those ground balls are coming against off-speed stuff, maybe as Cano cheats just a bit on fastballs and leaves himself more vulnerable to breaking balls.

Given the ages of Cano, Cruz and Hisashi Iwakuma and all the innings Felix Hernandez has logged, it's almost now-or-never time for the Mariners, especially considering the poor state of their farm system. They'll need Cano to start swinging right out of the gates in 2016. My take is that Cano was hindered in the first half and he'll have a better season in 2016, although he's probably not a top-six MVP candidate like he was each season from 2010 to 2014. Still, he should be good enough to anchor the Seattle lineup alongside Cruz and Kyle Seager.

Oh, and regarding the Hall of Fame: I think Cano is pretty close to a lock. With 55.1 career WAR, he's already closing in on recent second base inductees:

Ryne Sandberg: 67.5

Roberto Alomar: 66.5

Craig Biggio: 65.1

Jeff Kent, who has struggled to receive much support, is at 55.2 (although it should be noted that Lou Whitaker and Bobby Grich both rank higher than Sandberg/Alomar/Biggio and received no support). So voters have sort of established a rough cutoff at around 65 WAR, which Cano will reach with three more seasons of 2015-level production. Cano, who is already sitting at 2,015 hits, also has a decent chance at 3,000 hits given his durability."The Bill James Handbook" estimates his HOF chances at 42 percent.

But that's all down the road. For now, Cano just wants to get off to a good start in April.