Scouting And Grading Position Players
The 20-80 grading scale is used to evaluate the six core tools for position players. Those tools are:
Hit - Answers the question of "how well can a hitter hit a baseball?". It is a combination of innate for the barrel, hand-eye coordination, actual swing mechanics which can get very complicated and technical, eye (can the hitter discern different types of spin), strike zone knowledge (does the hitter know where are the edges of his/her strike zone), plate discipline (can the hitter lay off pitches at the edge of the zone), pitch selection (does the hitter swing only at fastballs, only swing at low pitches), swing decision (why did the hitter take the hanging slider at the middle of the plate or can the hitter adjust in the middle of an at-bat), and intelligence at the plate (does the hitter game a game plan when the hitter enters the batter's box).
All of those things encompass the most complicated tool in baseball to evaluate. Even for a player with a high batting average, it is still tough to determine a player's hit tool, as it is important to watch the player's at-bats in detail.
Raw Power - Answers the questions "how hard can a hitter hit a baseball?" and "how far can a hitter hit a baseball?". It is usually answered by data gathered and looking at a hitter's maximum exit velocity. In the Major Leagues, just type " (player x) savant" or " (player x) Fangraphs" on search engines, then information can be obtained. For the Minor Leagues, though, it's different. There are sites like FanGraphs that have the data but it is incomplete and for an actual scout in the field, on-hand data is not available unless asking a ballpark personnel in-person.
For that, there is a handy guide that is available on FanGraphs' Eric Longenhagen and ESPN's Kiley McDaniel's book "Future Value". The duo mentioned a chart that McDaniel used when he was with the Yankees that determines a player's raw power with the distance of the baseballs hit during batting practice with all the elements being equal (wind, swing effort, baseball quality, etc.).
Let's say a right-handed hitter is doing batting practice. If that furthest-hit ball hit by that hitter traveled only to the left-field foul pole, it's a 40-grade raw power. If it is only to the left-center gap, it's a 45-grade raw power. If it is to the center-field warning track, it's a 50-grade raw power. If it got over the right-center field gap, it's a 55-grade raw power. If it got over the center-field fence with a set distance of 400 feet, it's a 60-grade raw power. If it got over the center-field fence and got over the wall by around 30-40 feet, it's a 70-grade raw power. And if it got over 50-feet, it's 80-grade. It's not the most accurate of depictions of raw power, but if you are planning to do some scouting with nothing but your eyes, it's a pretty handy guide to have.
Game Power - Answers the question of "how well can a hitter use his raw power in a game?". Home run total is the simplest answer, especially in the Minors, because of a lack of data. However, not all home runs are created equal. In the Majors, average exit velocity and 90th percentile exit velocity are better indicators of power than home run total. In the Minors, FanGraphs has average exit velocity, but it is incomplete for several players. Digging deeper and exit velocities can also be found on team-run accounts on Twitter like @sfgprospects and sites with access to Synergy data.
Looking at isolated power (ISO) or the difference between slugging percentage and batting average is tricky because speed can affect the number. If a player didn't exceed hitting five home runs but has at least 25 doubles and five triples to his stat line, it will probably result in a pretty good ISO grade.
The most important factor for game power is the swing itself. If it's a line-drive swing or a swing with a flatter bat path, it will usually result in low home run numbers even though the hitter can still hit the ball hard. The hit tool and the overall approach in the batter's box also affect game power a bit, with the approach more in play over the hit tool, but are not the deal-breakers when determining a player's game power tool.
Speed - Answers the question of "how fast is this player?". Raw speed is the easiest tool to grade in-game as it only needs one piece of equipment: a stopwatch, either an actual stopwatch or the stopwatch function on a smartphone. Raw speed can easily be graded by measuring the time it took for a batter to get to first base from the batter’s box after the ball made contact with the bat.
What makes speed the easiest tool to measure during film study is that it can be done during a game, whereas raw power takes place pre-game and has to be evaluated in-person or rely on outside sources. For high school prospects, raw speed can also be measured by looking at 60-yard dash data if available.
Like raw power, raw speed is only as good as how a player uses it in-game. For example, a player has 70-grade or plus-plus raw speed but that player is only successful in stealing bases at only a 50% clip. It knocks down his final speed grade a bit to potentially a 60.
Speed is often associated with base-stealing, but it is also associated with the range in defense. It might be tough to have a certain player to stick at shortstop with a fringy-grade speed unless that player plays insane defense at shortstop or for a center fielder stick up the middle.
Arm - Answers the question "how hard can he throw on defense?". The arm tool is an easy tool to evaluate for catchers but a tough tool to evaluate for infielders and outfielders. For catchers, it is measured by pop time, or the time elapsed from when the ball hits the catcher’s mitt to when the intended fielder catches the throw.
Like raw speed, it can be measured by a stopwatch and the quicker the pop time is, the better. The pop time grades that are on the grading scale are the average of Isaan Sethi of Saberscience’s study on pop time grades using Statcast data and the average of Baseball America’s pop time ranges in their 20-80 grading scale.
For the other seven position players, it is hard to evaluate because there is no data available on arm strength from throws to first base by the defenders in the Minors unless they had a history of throwing on the mound and the velocities on their fastballs are known. For high school turned pro prospects who attended showcases to show off their arm strength, their velocities are available, but it is important to watch their fielding drills, particularly infield drills, the effort when throwing as plenty of prospects nowadays overthrow. For outfielders, overthrowing is more tolerable but must still be accurate to home plate during actual games. Outfield assist is an unreliable stat to use because of the nuances in play (e.g., a left fielder throwing out a runner on third base).
If there is no other choice, eye-balling is the only way. A good rule of thumb to use is to use the base runner's speed tool. If a base runner has plus speed and a shortstop, for example, threw him out in a bang-bang play, that shortstop will usually get a plus arm grade. This method needs a good sample size to produce a solid assessment.
Another aspect that affects the arm grade is how well can a player make off-platform throws in multiple arm angles consistently while maintaining their accuracy. People in the scouting community call it "arm utility". People who watch the NFL will associate arm utility with Patrick Mahomes.
Essentially, if a player can keep their arm strength and accuracy while throwing on the run, bare-handed, on his knees, or even on his back, while jumping to the air, while spinning, with his momentum taking him away from first base for an infielder, throwing sidearm, throwing underhand, and throwing from a high arm slot aside from the routine throws.
Field - Answers the question of "how well can he defend his position?". Grading defense in the Minors is quite challenging because most prospects will struggle with errors associated with reps, although the players who are good on defense stand out because they can make the plays that you will usually see big leaguers make.
There are three levels of defense. First off is with the catcher position. The key things to look for when grading catcher defense are agility, framing, and mental ability. For agility, having active legs and effort when preventing passed balls and wild pitches is highly important. Blocking balls in the dirt with the chest pad instead of picking with the mitt is still preferred, even though it is labor-intensive. Agility is also clear on a catcher’s get off from the crouch when throwing out base-runners or fielding balls in play.
The second is framing. It might not be important in the next three years, but with framing still a countable stat, it still matters. Personally, framing is not highly important, but having a soft mitt when catching high velocity and breaking balls is essential.
The third and the most important part is the mental side of the game. Building rapport with your pitching staff, knowing what the pitcher currently has confidence in throwing, knowing what pitches or area of the strike zone does the opposing hitter struggles to hit, understanding swing outcomes, and creating a plan on the fly to attack those said swing outcomes or even thinking further ahead for a smart hitter to get a hitter out.
Personally, a catcher does not need to be the leader of the entire field, but he has to be the leader of the battery. Playing catcher is a highly stressful job but as the only player who can see the entire field, controlling the outcome of the game with the brain and calling the right pitches is entirely possible while the other eight defenders only have to react to the sight and sound of the ball to affect the outcome of the game.
For both an infielder and an outfielder, playing with grace is the most important thing in defense. Being able to move loose and free in space with excellent body control, being light and efficient with their footwork, quick first step and reaction time when reading and predicting ball trajectory, getting low to the ground for infielders and running clean routes for outfielders, and their respective arm and speed grades are the nuances to look out for.