Ted Williams may be the greatest Red Sox player of all time. David Ortiz may currently be the most beloved. But I’d like to make the argument that Carl Yastrzemski is simply the most Red Sox player of all time. Yaz was nearly unique in Red Sox lore in that he played for over two decades, only spent his career with a single franchise, and possessed both longevity and an astounding, productive, nigh-magical peak. If it weren’t for the long shadow cast by Williams, one of the game’s five greatest hitters, perhaps Yaz would be considered the greatest player in franchise history.

Instead, perhaps he can settle for being the most emblematic player to don the colors of Fenway. Yaz was steadfast and sure, capable of great peaks and the producer of a long, storied history. He never made it to the top of the mountain, so his struggle to win the World Series could mirror that of the team’s 86-year drought between victories. His career may even also mimic the struggle in the shadow of the more popular, more anointed team in New York. No matter how or what the Red Sox do, they may never be able to eclipse the sheer scope of the Yankees, the same way Yaz’s accomplishments must always be compared to that of Ted Williams.

Today, let’s pull the career of Yaz out from Williams’ shadow, and examine it in the context of modern sabermetric stats. We’ll review the things he did well and the memories he helped to create.

Yaz was nearly unique in Red Sox lore in that he played for over two decades, only spent his career with a single franchise, and possessed both longevity and an astounding, productive, nigh-magical peak.

Yaz began his career taking over for Williams in left field in 1961, at the young age of 21. During his first season he showed few signs of the incredible hitter he’d become–his True Average of .249 was the worst it would ever be in his career, though that was still just a bit below league-average. He also didn’t cover himself in glory in regards to his defense, as his -2.2 FRAA in left field would turn out to be one of the worst marks of his career. But there were flashes: despite a .266 batting average, he managed to earn a respectable .324 OBP thanks to a combination of solid approach at the plate and a plus feel for hitting. His arm was already a valuable asset, and he began to learn how to play off his home stadium’s signature feature: the Green Monster.

By the time 1962 rolled around, the “real” Yastrzemski was ready to emerge. First, the defense came around. Yaz earned 18.8 FRAA in left field–think of Alex Gordon’s defensive prime–and began to establish himself as truly elite in that position. Despite left field defense often being looked at as inferior to those players in the center of the diamond, Yaz began to add between a win or two of value each season thanks to his instincts, his ability to play balls off the wall, and his rifle arm. In addition, he had three major pillars of offensive success starting to develop: bat-to-ball ability, power, and a keen batting eye. Though not possessed of Ted Williams’ once-in-a-generation eye, Yaz was already starting to rack up a healthy on-base percentage (.363 that season) thanks to the ability to draw a walk and make solid contact. Finally, he posted 19 home runs, but also 43 doubles. He was starting to emerge as a true offensive threat as well as a defensive force.

In 1963, Yaz officially broke out. He earned 7.4 WARP (fifth among position players in all of baseball and second among position players in the American League) on the strength of his combination of defense and offense, finding himself sixth on the AL MVP ballot while earning an All-Star appearance and a Gold Glove. He won his first batting title, and led all of baseball with a .418 OBP–the first five AL OBP titles he’d win over his career. His .328 True Average was one of the best in the game, far better than what he’d posted before and the mark of a well above-average hitter, even for a corner outfielder.

Over the next three seasons there would be ebbs and flows, but Yaz established himself as a consistent, top-flight young outfielder. In 1964, his power dipped a little, but it rebounded in a big way in 1965 when he hit 45 doubles and 20 homers, good for a .536 slugging percentage. He had a surprising defensive dip by FRAA–the BP metric for defense rated him as slightly below-average despite three consecutive stellar seasons–but by the next year he earned enough fielding runs to make up for that lull. His 31.0 defensive runs by FRAA in 1966 is an astonishing feat; that’s more than three wins of value in defense while spending most of his time in an outfield corner. Despite slipping into bit of an offensive lull, he still played above an All-Star level, with above-average offense, stellar defense, and good all-round skills. But the best was about to come.

Let’s take a moment and talk about 1967. ‘67 was a big year for the Sox as a team–this was the “Impossible Dream” team that made it to the World Series only to run into the unstoppable force that was Bob Gibson. Yastrzemski was a force in that Series, with three home runs in 30 plate appearances and a .400/.500/.840 triple-slash line. He did everything he possibly could to push the Sox to the brink in seven games, but the team could not overcome the Cardinals and win the championship.

Before that ever happened, however, Yaz led up to that point with one of the greatest single seasons in MLB history. After years of 10-20 homers, Yaz’s power finally broke out, and he dominated the American League offensively. First, there were his 44 homers, which tied him with Harmon Killebrew for the league lead. He also led the AL in batting average and RBI, granting him the Triple Crown, a feat that would not be replicated in baseball for nearly 50 years. He led all of baseball in OBP (.418), slugging percentage (.622), and just for good measure, True Average (.373) … lest you think those big numbers were just a creation of hitter-friendly Fenway Park. And, of course, he paired it with his solid signature defense. When you put it all together, you get an 11.8 WARP season, one of the highest in baseball history, and a season that would go down in the books as one for the ages.

Yaz would lose out on a unanimous MVP award thanks to one voter’s decision to go with Cesar Tovar over him. For the record, Tovar earned 2.9 WARP while manning second base for the Twins that season, and the Twins were a good team. But that makes for an 8.9 WARP difference between the two ballplayers, which is an unforgivable gap no matter how big the error bars on WARP may get. For reference, that would be like the National League MVP voters this season choosing Daniel Murphy over Bryce Harper last season. Not a good look.

Yaz would never be as great again as he was in ‘67, but few players in MLB history have ever put up a season that excellent, so we can forgive him. But in 1968, he’d try. He was once again an outrageous offensive force, but this time he traded much of his power (just 23 homers) for an increase in walks and a .428 OBP, which led all of baseball. Of course he missed out on the MVP award this year, as Denny McLain won 31 games, and the pitcher win was king at the time, but Yaz also fell behind teammate Ken Harrelson and a trio of Tigers position players in the voting, among others. He came in ninth in the AL MVP race, despite racking up 10.3 WARP. (Fun fact: he also won the AL batting title with a mere .301 batting average, which is the lowest batting average to ever lead that particular leaderboard.)

1969 was a bit of a down year, but this was primarily due to uncommon bad luck on balls in play. During that season everything else seemed to be working for Yaz: he crushed 40 homers and walked 101 times, but his batting average for the season only reached .255, which would end up being the third-lowest mark he’d ever post in the big leagues. How did last season’s batting champ let things get so low? Despite a career .290 BABIP (and that takes into account the lower BABIP during his career twilight), Yaz only had a .241 BABIP during this season thanks to, likely, dumb luck. A regular batted-ball distribution would’ve resulted in another MVP-caliber season, instead of a comparatively-low .298 TAv. The expected rebound came the next season, as in 1970 he hit another 40 homers … only this time he ran his average back up to .329, led his league in OBP (.452) and slugging (.592), and came in fourth in the MVP race. Oh, and if he’d posted his typical FRAA numbers out in the field instead of the surprisingly-low 6.8 mark of that season, he probably would’ve posted a third 10+ WARP season.

The only recent examples of dominance to start a season that I can think of to compare to Yaz’s decade-long debut are two guys who currently play for the Angels: Albert Pujols and Mike Trout.

So let’s take a break to examine just how great Yaz’s first decade was by the black ink markers. He found himself on the MVP ballot in eight out of 10 seasons, and won the award once. He was selected to seven All-Star games and won five Gold Gloves. He posted a .390 OBP, a .496 slugging percentage, and 66.3 WARP. Can you actually believe that? You know what kind of players average six and a half wins per season? The absolute greatest ones. Miguel Cabrera, another Triple Crown winner, is a no-doubt Hall-of-Famer and one of the game’s premier players. Over his 10 best seasons, he posted 57.4 WARP … and that’s with the benefit of cherry-picking just the best ones. The only recent examples of dominance to start a season that I can think of to compare to Yaz’s decade-long debut are two guys who currently play for the Angels: Albert Pujols and Mike Trout. The list ends there.

Anywho, after 1970, Yaz would continue to grind away at left field and first base for the Red Sox, but his peak was over. In the next 13 seasons, he’d amass plenty more hardware: 11 more All-Star Game selections, another Gold Glove, and spots on six more MVP ballots. But he’d never again win a batting title, lead the league in an important offensive category, or post a six-WARP season. He’d embark on what amounted to a second career: solid regular with occasional flashes of five-win brilliance (‘71, ‘73, ‘77). His True Average marks would rise and fall, but most often would hover around .270-.280, making him a better-than-average hitter, but not much more than that. His defensive brilliance faded into quiet consistency, especially as he transitioned to first base from the outfield.

By the end of his career, he owned many of the Sox’s career records, including games played, plate appearances, runs scored, RBI, hits, doubles, intentional walks, and more. (Miraculously, both Dewey Evans and Jim Rice beat him out for the strikeouts record!) He sauntered into the Hall of Fame with 94 percent of the vote, and his number eight has been retired by the team. He was an absolute fixture for over two decades, and was a valuable, effective player at the least for nearly all of them–an elite peak plus elite longevity.

There are probably just two things I’ve done with any consistency over the past 23 years: watch baseball and enjoy brownies. That’s it. I can imagine things that I’ll continue to do and enjoy from now to a point two decades down the line, sure … but even still, doing any one thing for a quarter of a century seems so long. Timeframes of that length stick in my head as esoteric concepts like special relativity and string theory–as hard as I try to wrap my head around them, I just can’t do it.

It’s possible that this is the first time Carl Yastrzemski’s career has been compared to a concept like time dilation, but there was certainly a gravity to Yaz. He was solid, sure, and true. The further that we’ve moved from his orbit, the clearer we can see what he was. No other player in the history of this franchise will ever eclipse his marks in longevity, I’d bet; the game is no longer designed to give players 23-season careers, let alone with a single franchise. As much as you may love Mookie or Xander, can you honestly imagine them starting for this Red Sox team in 2035 or beyond?

For that reason, among others, I decline to do as I often do and point toward a player currently in the organization who compares to my subject. To call a Red Sox player the “next Carl Yastrzemski” is to do to him the same disservice as calling him the “next Ted Williams.” No man should be expected to hold his own for 23 seasons, to be the most valuable player in the league, to be a first-ballot Hall-of-Famer. Carl Yastrzemski was a singularity, doing all the amazing things we expect from a baseball player but at a scope that stretched longer, deeper, and broader than anyone could have hoped. If that’s not representative of this storied franchise, I’m not certain what is.

Photo by Greg M. Cooper/USA Today Sports Images