Mike Moustakas slugged his way through one walk year, then another, then another. A hundred and one homers later, now in his third straight offseason of free agency, the 31-year-old third baseman is chugging along as strong as ever.

A late bloomer on offense, Moustakas has become a model of consistency. After starting his career with four years of well-below-average production at the plate, he's been solidly above average every season since breaking out 2015. He was a key middle-of-the-order hitter for a World Series champion Royals team and back-to-back Brewers playoff teams.

Moustakas' OPS+, 2015-19
2015: 119
2016: 110 (played only 27 games; torn ACL)
2017: 117
2018: 107
2019: 114
League avg. = 100 || 101 = 1% above avg.

By now, you know what you're getting from Moustakas. That's a good thing. He's a proven valuable player to have in the lineup. He just needs to find the right team, again.

Moustakas seems to be overshadowed again this offseason, really through no fault of his own. Fellow free-agent third basemen Anthony Rendon and Josh Donaldson are bigger stars with more impressive resumes, and third base is a deep position in the Major Leagues.

? Latest Hot Stove news and rumors

But that undersells Moustakas. There might be a lot of star power at third base these days, but not every team has the hot corner locked down. Only a handful of third basemen have a five-year run as consistent as Moustakas at the plate.

Moustakas has four full seasons as an above-average hitter (by OPS+) in the last five years, the lone exception was his injury-shortened '16. Only five other third basemen can say the same: Nolan Arenado, Rendon, Kris Bryant, Manny Machado and Jos¨¦ Ram¨ªrez.

The last three seasons in particular -- the ones preceding each of his free-agent winters -- Moustakas has taken off from a pure power standpoint, averaging 34 home runs. He's one of only four third basemen with 100 homers since '17.

Most HR by third basemen 2017-19

1. Nolan Arenado (COL): 116
2. Eugenio Suarez (CIN): 109
3. Manny Machado (SD): 102

4) Mike Moustakas (FA): 101
5-T) Alex Bregman (HOU): 91
5-T) Jos¨¦ Ram¨ªrez (CLE): 91

Those other players are locked up on long-term deals. Moustakas is older than them at 31, but he should still have plenty of productive years, and there are ways Moustakas has gotten better over the last few seasons.

Look at Moustakas' contact quality -- specifically, his hard-hit rate and his barrel rate. Statcast defines a hard-hit ball as being hit at least 95 mph. Go one step beyond that, and you get a barrel, the best kind of contact a hitter can make. A barrel is a ball hit with both ideal exit velocity and ideal launch angle (as in, hit hard and in the air), the kind of ball that's most likely to be a home run or an extra-base hit.

Moustakas' hard-hit rate and barrel rate are both trending up. Here they are for his four full seasons since Statcast began tracking in 2015 (excluding the injury-shortened 2016).

Moustakas' contact quality, since 2015
2015: 37.1% hard-hit | 6.6% barrels
2017: 33.8% hard-hit | 8.6% barrels
2018: 39.1% hard-hit | 8.8% barrels
2019: 40.7% hard-hit | 10.3% barrels

The 2019 season gave Moustakas personal bests in both categories, and he was well better than the average hitter (the overall MLB hard-hit rate was 36.6% this past season; the MLB barrel rate was 7.4%). Those underlying numbers matter -- make better contact, and you should get better results.

And to the point that sluggers can have a harder time in free agency now, with the proliferation of power around the game: yes, Moustakas is a typical lefty power bat at the corner infield ¡­ but he's also shown his adaptability on the field.

Moustakas is a fine defender at third base, his primary position. But the Brewers needed flexibility from him in 2019, playing him at second base 47 times in addition to his 105 games at third. He was capable at both positions -- right around a league average third baseman and second baseman, by the defensive metrics.

Someone who can man both a corner and a middle-infield position while also bopping 30 homers in the middle third of the lineup is a useful player to have. Combine Moustakas' offense and his defense, and you get a player who's been at least at the "solid starter" level by Wins Above Replacement in every full season since 2015 (3.8 WAR in '15, 2.0 WAR in '17, 2.4 WAR in '18 and 2.8 WAR in '19, per FanGraphs).

Compare Moustakas to a fellow free-agent slugger like Marcell Ozuna, whose offensive production has been similar to Moustakas' over recent years, but who was one of the worst defensive outfielders by Statcast's Outs Above Average metric in 2019. Say you're a National League contender looking for a solid free-agent bat. Who would you rather have, a power hitter who can handle two infield spots, or a power hitter who might cost you runs in an outfield corner?

And if you need that offensive-minded infielder, you already have a nice idea of what Moustakas can do.