Sportico is proud to partner with The Harvard Sports Analysis Collective, a student-run organization dedicated to the quantitative analysis of sports strategy and management, to bring our readers the excellent work coming from some of the brightest young minds in the country.
In what world would Starling Marte make an All-Star Team over Mike Trout?
For decades, scouts have evaluated players on the five tools—contact hitting, power hitting, speed, fielding and throwing—but even now, there is no standard definition, no widely accepted quantifiable measure for each skill. Here, we’ve tried to set some: Using advanced metrics, we created a method for determining the best five-tool athlete at each position to make up an All-Around All-Star Team.
And our results may surprise you. While Marte certainly lacks Trout’s superstar talent, he can claim at least one thing over the Angels phenom: Marte is a five-tool player.
Measuring the Five Tools
Contact: A player’s contact rate is commonly defined as the percentage of at-bats in which the player does not strike out. At-bats are used instead of plate appearances in order to exclude the effect of walks, but at-bats also exclude sacrifice flies, which are instances when a player successfully makes contact. We modified the standard measure of contact rate to include sacrifice flies, changing contact rate to (At Bats + Sacrifice Flies – Strikeouts) / (At Bats + Sacrifice Flies).
Power: Many stats assess power, but most of them fail to capture true ability. Home run total is widely cited, but it does not account for stadium differences. Exit velocity (EV)—the speed that a baseball leaves a player’s bat upon contact—is also a flawed measure because it does not include the effects of launch angle; a player who hits a ball hard into the ground will not help his team as much as one who blasts the ball in the air.
A player’s percentage of barrels (out of total batted balls) more accurately measures power, since this statistic factors in both EV and launch angle. In order for a ball to be classified as barreled, it must have an EV of at least 98 mph and a launch angle within a certain range.
Speed: While several statistics measure running skills in baseball, Statcast’s Sprint Speed metric measures it most literally. It looks at a runner’s “fastest one-second window” on runs of multiple bases (such as first-to-third on a single) and when running from home to first on weakly hit balls. The average Sprint Speed for all players is 27 feet per second, but significant variation exists across positions.
Fielding: For non-catchers, Statcast’s Outs Above Average (OAA) is an objective measure of fielding because it employs radar technology and cameras to gather positioning and motion data. OAA rewards fielders for making challenging plays and penalizes them for missing easier ones.
OAA does not exist for catchers, whose defensive skills are not as focused on running to batted balls. Fielding Bible’s Defensive Runs Saved (DRS) measures catchers’ fielding abilities by estimating the number of runs saved in the field and by framing and selecting pitches. DRS also measures runs saved by preventing stolen bases; however, since this metric is largely dependent on arm quality, which is a separate tool, we subtracted this stolen base component from DRS to measure the fielding tool for catchers.
Arm: There is no statistic that accounts for throwing talent across all positions. For catchers, Statcast’s Arm Strength measures the average velocity (in miles per hour) of a catcher’s fastest 10% of throws on stolen base attempts. For outfielders, the arms runs saved component of DRS assesses arm strength; this measure looks at how often runners try to take an extra base against an outfielder and how often the outfielder throws them out. For infielders, there are no publicly available measures of arm strength, so we calculated throwing accuracy by dividing a player’s throwing errors by the number of batted balls in his fielding zone.
We determined a player “had a tool” if he was above average in 2019 relative to others in the same position. The player with the most tools at his position made our All-Star Team. If multiple players tied for the most tools at their position, we used the harmonic mean of each player’s percentiles for the five tools as a tiebreaker. Unlike a typical average, the harmonic mean tends toward lower numbers in a set. As a result, it is better for capturing well-rounded players, instead of those who especially excel in one area of the game.
Although no catcher was above average in all five tools last year, the Phillies’ J.T. Realmuto had the strongest arm among catchers, and he was also the second fastest. He just barely missed the fielding tool, ranking in the 45th percentile.
Realmuto was selected as a reserve for last year’s actual All-Star game, but interestingly, neither the American nor National League starters—the Yankees’ Gary Sanchez and the Cubs’ Willson Contreras—made our top five. Sanchez was below average in contact, speed and defense, and Contreras was below average in contact and defense.
Atlanta’s Freddie Freeman was the only five-tool first baseman last year, and is thus a decisive pick. Although he did not dominate in any category, Freeman posted strong numbers in every tool; in his worst tool, fielding, he still ranked in the 61st percentile. Out of all of the players in our sample, only Cody Bellinger ranked higher in each of the five tools. Freeman hit a career-high 38 home runs last year, and his strong barrel percentage (70th percentile) surely helped him along the way. Perhaps Freeman would have been even more impressive had he not suffered (and played through) an elbow injury late in the season, one that later required surgery.
Detroit’s C.J. Cron led the four-tool first basemen in harmonic mean, and he was merely one OAA away from being a five-tool player. This may be surprising, considering he is only a 1.7 bWAR player and analysts do not talk about him as a top-class first baseman. Given that he has been on four teams in the past four years, his own teams do not appear to value him highly either.
Interestingly, former All-Star first baseman Eric Hosmer was one of only four MLB starters to possess zero tools.
Before 2019, it would have been surprising to see the Diamondbacks’ Ketel Marte atop this list. However, he exploded with 7.2 bWAR last year and finished fourth in the NL MVP race. This was mainly driven by the 32 home runs he launched, which was more than his previous four seasons combined. Still, these power numbers were no fluke, as Marte ranked second among second basemen in barrel percentage.
Ketel Marte struggled on defense last year, splitting time between the infield and outfield. However, the team’s addition of centerfielder Starling Marte (more on him later) allows Ketel to settle in at his more natural position, second base. Look for Ketel Marte’s defensive numbers to catch up with his offensive output this year.
Looking to the next generation, Ozzie Albies of the Braves, by our measures, shows the most promise. The 23-year-old’s weakest tools were contact hitting and defense, but he still shows off talent in these areas. For example, his 189 hits paced the National League, and according to Fielding Bible, Albies ranked third in DRS among all second basemen.
No surprise, but the lineup of shortstops was very crowded. Nick Ahmed edges out a spot on our team, helped by his sensational defense. Ahmed is a two-time Gold Glove Award winner, and he tallied 16 OAA last season. Despite narrowly missing out on the cutoff for power, Ahmed has shown growth in his power numbers, boosting his home run total in each of the last four seasons. If he continues this trend, the Diamondbacks, with Ahmed and Ketel Marte, may boast the top double-play combo in the league.
Marcus Semien matched Ahmed as the most talented of the four-tool shortstops (based on the sum of the five percentiles), but his -4 OAA ranked so low it took him out of contention. Nevertheless, other metrics value Semien’s defense more than OAA, and he was chosen as a finalist for the Gold Glove in both 2018 and 2019.
Two players emerged with all five tools in this group, but only barely. Anthony Rendon of the Angels—our top pick at third base—and Seattle’s Kyle Seager each finished in exactly the 50th percentile on defense, and Seager was in the 50th percentile for contact as well. Meanwhile, Matt Chapman had the opposite problem: He excelled in four areas of the game, but struggled to hit for contact. Therefore, he was relegated to being the best player (as measured by the sum of all five tools) who did not make our team.
Rendon continued to do it all last year, leading the league in doubles again while also playing solid defense. However, nothing can top his biggest accomplishment—piloting the underdog Nationals to their first World Series title.
Some might be surprised that Alex Bregman is not among the top five third basemen, given that he led the American League in bWAR and blasted 41 home runs. But remember Bregman hits many fluky home runs; he finished 240th out of 249 hitters in average home run distance last year. Due to his low barrel percentage and mediocre throwing arm, Bregman failed to make our final list.
Cody Bellinger, Starling Marte and Mookie Betts make up our starting outfield. The 2019 NL MVP, Bellinger easily earned a spot on the team. He was, by our measure, the strongest five-tool player in baseball. Marte qualified for our team because he was the only other five-tool outfielder, although he barely made the cut for fielding (50th percentile) and power (54th percentile). Betts only possessed four of the five tools (missing speed), but he was dominant in each of the four, meriting the final spot in the outfield. And while Betts isn’t an elite sprinter, he is an excellent base runner. When HSAC explored the five tools of baseball in 2017, Betts rated as one of the ten best baserunners even as he finished outside the top 100 in sprint speed. It will be fun to watch Bellinger and Betts team up in the Dodgers’ outfield.
Perhaps it is surprising to find that Mike Trout is missing entirely from our list of the top 10 outfielders. While he is among the best in several aspects of the game—ranking in the 99th percentile for power, for instance—Trout only possesses three tools, according to our study, due to his below-average fielding and above-average strikeout percentage.
We had to make several tough decisions when forming our team. When quantifying how many tools each player had, we classified players as possessing a tool if they reached the 50th percentile for their position. In reality, there is little difference between players at, say, the 48th and 50th percentiles, but this proved to be the deciding factor between some players making the team over others. Even though Twins centerfielder Byron Buxton outperformed Starling Marte on four of the five tools, he ranked just below the cutoff for contact. Meanwhile, Marte just reached the cutoff for defense, enough to snag Buxton’s spot.
We also required players to have fielded a position in at least 82 games to make our team. However, this cutoff caused some utility players to be ineligible at every position. DJ LeMahieu, for example, played 145 games last year, but did not amass 82 appearances at any position. LeMahieu would have rated above-average at second base in every tool except speed.
When selecting players for the All-Tool team, we first ranked players based on the number of tools they had and then used the harmonic mean as a tiebreaker. As a refresher, the harmonic mean is another form of an average, which skews towards lower values. Therefore, it emphasizes well-rounded players and ensures that even on their worst tools, the players we choose still do decently well.
For no player is this more evident than Bellinger, whose harmonic mean of 84.9 across all five tools dominates all other players. Even on his worst tool, speed, Bellinger still ranked among the top 25 outfielders. And at only 25 years old, he has yet to reach his prime.
Few players can excel in every part of the game like Bellinger. Even if they aren’t as well-rounded as the Dodgers’ star, some players can compensate for their weaknesses by racking up value in other aspects of the game. The following graph displays the players who are the “toolsiest” and have the highest combined score across all five of the tools.
Unsurprisingly, Bellinger tops this list too. However, two of the next three players on the list did not possess all five tools: Matt Chapman and Byron Buxton, whose struggles with strikeouts prevented them from being named to the five-tool team.
Four of the top six players in terms of the sum of their percentiles across the five tools made the all-around team. In the end, the top players at each position were J.T. Realmuto (catcher), Freddie Freeman (first base), Ketel Marte (second base), Nick Ahmed (shortstop), Anthony Rendon (third base), and Cody Bellinger, Starling Marte, and Mookie Betts (outfield).
Using Baseball Reference’s Wins Above Average (WAA), we can see how this team would compare to MLB squads from 2019. WAA is similar to Wins Above Replacement (WAR), but compares players to the league average. It is useful for estimating how a group of players, based on individual skill levels, would translate into a team record. Last year, the Houston Astros had the highest WAA total, with their starters combining for 20.1 WAA. Summing up the eight players in our team’s starting lineup, the All-Around All-Star team would blow Houston out of the water, with 29.5 WAA. If this team were supplemented by a league-average pitching staff, designated hitter and bench, it would still excel. If we assume an average team would go 81-81, this team would be expected to win roughly 110 games over a full MLB season.
Now that’s what we’d call a fantasy baseball team.