Evaluating the 2016 Prospects: Introduction and Primer

We have been working hard to get our team prospect rankings out to you as soon as possible. Starting with the Arizona Diamondbacks, the lists will proceed in alphabetical order by city and team name. As we start rolling out the organizational reports, I wanted to give you some guidelines for understanding my ideas and grades, to avoid confusion over why the grades here differ from other publications, even in cases where we may be saying the same thing. Though this will not be an all-encompassing article of my scouting opinions, it should provide the framework for our conversations on each of the team’s prospects.

I want to go through each of the five tools for hitters and the grades for pitchers, and explain basically what I believe are the most important factors going into them. Since some of you may not read this whole blurb, and then ask questions about why a pitcher who throws 95 only got a 50 grade on his fastball, I will admit to one overarching theme: functionality. How functional is that 95 mile-per-hour fastball if it’s straight and the pitcher who threw it has no idea where it’s going? Similarly, what is the use of an 80 grade for power if the hitter is blind and doesn’t also possess echolocation or some other means to hit a baseball?

One other difference for the way I’ll be communicating scouting grades to you is the presence of three numbers on each tool instead of just two, at least for the professional players. Here’s an example. Consider Rick Vaughn’s fastball before he was given his magical spectacles: 35/50/70. The first number is the current grade; it’s fast, but he can’t locate it, and when it does find the zone, it gets tattooed for a home run by a stereotypically douchy slugger. The second number is the likely future grade; he’s still young and not in prison, and he’s played by Charlie Sheen (the star of the movie), so you know it will get better. Still, the current state of the pitch makes it unlikely to be crazy effective, so an average future fastball could be the most likely outcome. Or, if you prefer percentiles, call this the 50th percentile projection. The third number is the ceiling grade, or 90th percentile projection, to help demonstrate the volatility and raw potential of a tool. I feel this gives readers a better sense of the possible outcomes a player could achieve, and more information to understand my thoughts on the likelihood of reaching those levels.

Kiley gave us a great conversion table last year for understanding scouting grades in an objective (though admittedly estimated) context. I absolutely loved the idea, especially because my brain tends to think more in terms of what statistical production a player’s future ability will produce, and then convert it into the more universally used 20-80 scouting scale. Here is my slightly altered version of the same table for hitters, followed by a breakdown of the individual tools:

Scouting Grades in Context: Hitters
Grade Tool Is Called Batting Average HR ISO Baserunning Runs Fielding Runs
80 80 0.320 40 0.300 12 30
75 0.310 35-40 0.275 10 25
70 Plus Plus 0.300 30-35 0.25 8 20
65 0.290 27-30 0.225 6 15
60 Plus 0.280 23-27 0.200 4 10
55 Above Average 0.270 19-22 0.175 2 5
50 Average 0.260 15-18 0.150 0 0
45 Below Average 0.250 12-15 0.125 -2 -5
40 0.240 8-12 0.100 -4 -10
35 0.230 5-8 0.075 -6 -15
30 0.220 3-5 0.05 -8 -20

Remember these are estimates of true talent that we are trying to project multiple years down the road. Please don’t hate on me in two years when a player with a 55-grade power hits 25 home runs. First, why be so mean? And second, scouting grades are an attempt to peg true talent. Even if a tool remains static for years, the statistical evidence of the quality of that tool can vary due to league adjustments to the player, hidden injuries, randomness, etc. Think of it like BABIP and UZR, of which you need a few years of data to know anything about where a player really stands.

While this will not be needed much for the team prospect lists, as another general reference, here is Kiley’s table that gives an excellent baseline to process what an overall grade means:

Scouting Grades in Context: Overall
Grade Hitter Starting Pitcher Relief Pitcher WAR
80 Top 1-2 #1 Starter —- 7
75 Top 2-3 #1 —- 6
70 Top 5 #1/2 —- 5
65 All-Star #2/3 —- 4
60 Plus #3 High Closer 3
55 Above Avg #3/4 Mid Closer 2.5
50 Avg Regular #4 Low CL/High SU 2
45 Platoon/Util #5 Low Setup 1.5
40 Bench Swing/Spot SP Middle RP 1
35 Emergency Call-Up Emergency Call-Up Emergency Call-Up 0
30 *Organizational *Organizational *Organizational -1

With those general points established, let’s examine the individual tools more closely.

Hitter Tools


  1. Contact rate
  2. Barrel rate
  3. Ability to adjust during swing
  4. Swing path 
  5. Bat speed

You could make a strong case for vision being included on its own, but numbers one and three infer the effects of having good vision to some degree. A quick note about vision for hitters: it has little to do with visual acuity, i.e. 20/20, 20/30, etc. It’s true that hitters can benefit from high acuity by picking up spin or slight differences in a pitcher’s delivery, but the ability to track a pitch and anticipate its path is much more relevant to a hitter’s success.

Contact rate is fairly straightforward, though you have to beware drawing conclusions based on small sample size. In limited looks at players, I’m more concerned with how often a hitter swings through hittable pitches in the zone, while also considering overall strikeout rates and adjusting for quality of competition. Barrel rate is a similar skill, but has some elements of swing mechanics and a higher level of hand-eye coordination to get the sweet spot of the bat to the ball.

Being able to adjust to speeds and locations is a must for projecting a player’s hit tool, since no hitter is able to know where every pitch will end up right out of the pitcher’s hand. This is mostly a mechanical quality, whether it be a sequential unfurling of the swing to avoid getting overcommitted at the start, or how a hitter maintains his balance on his feet when a pitch does not arrive at the plate in a predictable manner. The visual quality of this skill is about how early out of the pitcher’s hand, or even in the pitcher’s delivery, a hitter is able to anticipate pitch type, speed and/or location. This shows up most obviously in a hitter’s ability to hold back on tough chase pitches and recognize well-executed pitches in the zone without showing urgency in the box or last-minute checked swings.

Swing path simply refers to how deep in the zone the barrel has a chance to hit the ball and how long it stays on the line of the pitch. Since all pitches arrive at the plate on some kind of downward plane, hitters with slight upswings have a higher probability of making contact with a pitch on account of being on the same line as the ball for longer.

Bat speed, in my opinion, is overrated in general. Yes, if you took everyone in the population and put them in the batter’s box, there probably is a base speed at which a hitter has to swing in order to have a chance of hitting high-level pitching. Beyond that, I don’t see a huge correlation between the speed of the bat and how often a hit is created. I have seen at most a handful of successful amateur or low-level minor league prospects whose lack of bat speed was the reason I thought they wouldn’t hit. Even in those cases, there were reasons higher on this list that downgraded them before even considering bat speed. I won’t discount its uses entirely, as it makes up for other shortcomings in many situations. However, I feel that it is often a survival mechanism for hitters with inefficient swings or poor natural strength. It also isn’t of any use if the hardest hit balls are straight down at the ground or straight up in the air, which by default ranks it lower than bat path in relative importance.

Many swings that appear to be super fast only look that way because the bat has a longer path to get to the ball, or gets disconnected from the body earlier, and then has to be rushed to compensate for a poor start to the swing. On the flip side, some swings that look slow only achieve higher velocities through the contact zone, where the speed is actually useful for driving the ball. In the constraints of evaluating the hit tool, it can also be much more difficult to control a bat that is moving fast in directions other than through the ball, limiting the projectability of a hitter’s batting average and ability to lay off late-moving pitches.


  1. Bat strength
  2. Swing path
  3. Bat speed

Here is where my grades will probably differ the most from other scouts/analysts, since my focus is on how applicable a hitter’s power will be rather than how far he could hit it if everything lined up perfectly. Numbers one and two are close enough to be 1a and 1b. Bat strength is simply a way of expressing how much force the body is able to create behind the barrel. This can come from brute strength in one or multiple parts of the body, or from efficient sequencing, or both.

A good swing path is underappreciated in power projection. In batting practice, pitches are predictable, and hitters who swing down or across the ball can still muster enough juice to hit balls over the wall. Having a swing path that matches the flight of the pitch, or more appropriate to power production, the flight of the desired batted ball makes it more likely a hitter will be able to tap into his raw power in game situations. Otherwise, he better have an amazing ability to hit below the center of the ball regularly, and with enough force to make up for the non-flush collision of the bat and ball.

Bat speed can also be a big part of power projection, but more as an adjunct. You can swing a bat extremely fast, but if there’s not enough momentum transferred to the ball it still won’t carry like you would hope. Remember from physics class, collisions deal with the products of mass and speed transferring to another mass. Mass in this case comes from both the weight of the bat and the strength forced on the bat by the hitter.


  1. Stolen base skill
  2. Ability to take extra bases
  3. Raw speed

This is another category that may get some raised eyebrows when reading my reports. The order of this list is a bit misleading, since when seeing any player for the first time, I will still turn to stopwatch times. I prefer using stolen base attempts or home-to-first sprints rather than 60-yard-dashes for grading, since running 180 feet in a straight line is so out of place with what happens on a baseball field. I put raw speed third because I see many players with average or better speed that are never able to use it offensively, such that it almost becomes useless in actuality. Give me a guy who can read a pitcher or a count for a good opportunity to steal, or read balls in the dirt, or know when a hit puts an outfielder in a tough position to cut down his attempt to take another base. Raw speed can give you a ceiling, but the intelligence threshold of using this tool is high enough that it is not sufficient in estimating the value of that player’s running abilities.

Running speed is also given a lot of credit for beating out infield hits, turning doubles into triples and elevating power numbers, or fielding range. Because of that, you can’t ignore the effect it has on the other tools and discount it entirely. I just like the discussion about a player’s speed to be a bit more nuanced, since it’s a more interesting though difficult assessment.


  1. Staying grounded
  2. Softness and quickness of the glove hand
  3. Rhythm
  4. First step efficiency
  5. Raw speed

The best fielders use the ground effectively to stay balanced, make a quick first step, and redirect momentum. Putting yourself in a good position to anticipate the next move with the ball fits under this category as well. Players who strand straight up and don’t get into their legs when reacting to a ground ball or a throw from a teammate have less of a chance reacting well to bad hops or errant throws. The ability to have soft hands is imperative for any good fielder to deal with hard-hit balls or awkward throws from other players. The smoothness of the glove itself could even be more important than how the fielder positions himself, as it can make up for a lack of athleticism in a lot of plays.

As an off-shoot of positioning, staying in constant movement with the feet and body helps to time hops on ground balls, get momentum into throws on fly balls, and keep the body from locking up when the ball darts a different direction. Raw speed is certainly a factor in how many balls a fielder can reach, but effective range is more what we will be discussing with these grades.

For catchers, the fielding grade is weighted and assessed differently:

  1. Receiving/framing
  2. Blocking
  3. Game management

I hate the term framing; it denotes the catcher actively doing something while catching the ball, when the best “framers” look like they do very little and make things look smooth. On the receiving side of the position, I look for quiet movements without a lot of body motion while catching borderline pitches. Anticipation of the ball’s destination instead of reaction is key. The softness of the hands is vital, and I put high grades on catchers who make every pitch’s break and location look like they were completely intentional. Blocking is about more than just getting a body on balls, and quick reactions to pitches in the dirt are a good start. More importantly, though, the best backstop is one who stays sufficiently relaxed such that the ball won’t bounce far from him. You want the ball to look like it gets deadened by the catcher’s body, not bounced off a brick wall.

Game management is a little more of a feel determination. Pitch-calling is less of a concern for evaluating prospects, especially since the wealth of information pitchers and catchers get in advance reports makes this more about execution at the major league level. I look more at body language when the pitcher misses a target, or after a misplay in the field. Calling timeout to talk to a pitcher at the right time, even when it doesn’t work out, is another way to evaluate this part of a catcher’s game. It may not be borne out in the numbers, but the catcher’s biggest impact is how well he can help the pitcher’s performance. Estimates of the effect of receiving show how much this can swing a game in a team’s favor, and I strongly believe the psychological effect of a battery mate to be a difference-maker.


  1. Release time
  2. Body control
  3. Arm strength

The first two qualities are interrelated, and certainly tie into those listed in the fielding section above. I see a bigger spread in the time that elapses between a catch and subsequent release than I see in arm strength, even among major league fielders. I think more fielders separate themselves from their peers in that way than just basing a throwing grade on pure arm strength. More often than not, I’ll note the raw arm strength grade and explain why the overall grade goes up or down accordingly, and again, it comes down to functionality. Having a hose does no good if an infielder has to take three or four steps to get rid of a ball on a slow roller. The same thing goes for an outfielder on a tag-up play. Being able to catch a ball in a difficult spot and still be able to make a throw with a quick release tells me more about the impact he can make with his arm than the radar gun does.

Catcher pop times are judged in a similar fashion. You will see a higher grade from me on a catcher who can consistently be 2.00-2.05 seconds to second base than one who throws a 1.90 on a good feed but a 2.15 with a bounce on a running pitch to the glove side. It’s rarely that cut-and-dry, but I think you can see where I’m coming from.

Pitching Tools


  1. Command
  2. Velocity
  3. Movement

Similar to how fielders exhibit a wider spread in release time than arm strength, I believe command is the biggest differentiator between fastballs that end up above the average or below. I wish we had access to minor league velocity averages by level to really test this observation, but a scout once told me that he thought the average velocity in A-ball was higher than in the majors. I have come to agree with him on an empirical basis; at worst, I would say they are dead even. Though the average fastball velocity in the big leagues has only crept up slightly in the last decade, it is the staggeringly higher number of those guys who can command it to both sides of the plate that is truly astonishing. While there is an obvious correlation between velocity and fastball effectiveness, nearly every prospect throws hard enough for at least one scout to be excited about him. I imagine we will have some fun discussions about the hypothetical pitcher who throws 95 but only an average future fastball grade. Let’s embrace the nuance.

Movement includes alterations from the norm in every direction. Some sink, cut or run their fastballs, or, my favorite, seem to make them rise. All of these have different effects on the batter’s viewpoint, and all can be utilized to miss the barrel if the movement is drastic or sneaky enough. Yet another way for us to add some fun to forecasting a simple fastball.


  1. Intent
  2. Command
  3. Movement
  4. Velocity

You could substitute feel, arm action or deception in for intent and we are saying basically the same thing. The idea with any off-speed pitch is to disrupt the hitter’s timing or anticipation of its end point. Making it look like a fastball is more than half the battle. I feel like command is the second most important factor in an off-speed pitch’s viability, since even a loopy curve or change-up thrown for a strike down and away (just for example) is very difficult to hit. I remember a couple years ago an interesting series of articles in the Community Blog by Thomas Karakolis on this very subject.

Effective movement to me has more to do with how late it seems to change trajectory. Pitching coaches describe this as controlling the first ten feet of ball flight, or pitch tunneling. Another good test is to see how much the ball moves when it’s left in the middle of the plate or up in the zone. If you still see good movement on a mistake location, you know you have something there.

Velocity on off-speed pitches is usually just a descriptive tool to me, though there is something to be said for having pitches that don’t overlap in velocities to give hitters one more thing to which they need to adjust. I don’t really buy into the rule about changeups needing a certain separation from the fastball unless they have no movement whatsoever.


This will not be a grade found in the reports I write, though I will comment occasionally on an anecdote or a team’s opinion of a player’s makeup. I am a firm believer in makeup being the biggest factor in determining a prospect’s probability of reaching or exceeding his ceiling, but I’m not comfortable saying I have anything solid to hang my hat on in this department. It’s hard to be confident even in a feeling you get talking to directly to a prospect, as Eno Sarris and I discussed recently. People are very good at fooling themselves and others around them about their motivations, or work ethic. One guy’s intelligence is another guy’s “paralysis by analysis.” One player’s confidence is another player’s inability to utilize help from coaches or relate to teammates.

I will say I do appreciate how a player carries himself on the field in a given situation. I think there’s something to a guy looking like he knows he’s going to make a play on the next ball that comes to him, even in the middle of botching a couple plays in a row. How he walks back to the dugout after his third strikeout of the day, or whether he can at least act like he has a short memory when he gets back out on defense the next inning. Things like that will not make a player jump a full grade in my book, but may persuade me to skew a bit higher or lower on his upside.

This piece went longer than I hoped when I set out, but I hope you learned something, or at least will enjoy the prospect reports more because of it. I’ll keep saying it: I love talking baseball and really encourage you all to be active in discussing players and grades. I have already had a lot of fun going out to evaluate players in preparation for this year of prospecting, and I want to make sure it’s a positive experience for everyone who is interested in this type of content. Expect the Diamondbacks rankings tomorrow.

Dan is Fangraphs Lead Prospect Analyst, living in New York City. He played baseball for four years at Franklin & Marshall College before attending medical school. Follow him on Facebook and Twitter @DWFarnsworth.

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6 years ago

*tips cap* Simply fantastic. Thank you!

6 years ago
Reply to  Mo

“I’m so excited! And I just can’t hide it! I’m about to lose control and I think I like it!” — Pointer Sisters (1984) and me (now)