Prospecting in dynasty leagues can be one of the most challenging and frustrating parts of fantasy baseball.  But, it’s also one of the most rewarding experiences when things go right.  There’s no better feeling than uncovering a hidden gem that never appeared on a prospect list; having them go from a nobody to a Paul Goldschmidt.  At the same time, growing attached to an elite prospect only to have them fall victim to injury or bad performance is as infuriating as it gets. Paying large prices for an exciting prospect turned bust not only hurts, but it can ruin a fantasy team’s future.  There’s no easy way to figure out which prospects to draft, pick up, or trade for, and despite the wealth of resources out there, there’s no way to be absolutely certain about the chances of a prospect succeeding or failing in the majors.

Still, there are some common statistical indicators that can help fantasy prospectors find their way.  Often, analysts will point to plate discipline as a way to tell how prospects will fare once they climb the ladder to the big leagues.  Walk rate and strikeout rate are far from definitive measures of future success, but they can be helpful tools.  The most commonly cited of the two is likely strikeouts: it’s not rare to see a player denounced due to their high rates of swing and miss, or praised for their ability to avoid the strikeout.  The question is, how valuable are strikeout rates for evaluating prospects?

To figure out the accuracy of strikeout rates when it comes to top prospects, I gathered career minor league strikeout rates for every top-50 position player prospect from 2005 to 2009.  I used these parameters because most traditional prospect lists don’t stretch back much farther than 2005, and prospects past 2009 may not have gotten a chance to make their impact on the league fully known.  I could have gone back in time a couple more years, but 120 individual hitters from this period (keep in mind, most appear on the list multiple times) seemed like enough.

The results weren’t as strongly correlated as I had hoped.  There is certainly a relationship between strikeout percentage and WAR, but there isn’t enough evidence to firmly say that a prospect with a strikeout rate above a certain point will fail, or vice-versa. All we’ve been able to glean from the data so far is that a higher strikeout rate isn’t ideal, but it also isn’t exactly a death sentence.

There are always one or two players that can succeed despite a high strikeout rate or flop even with a low strikeout rate–as the ‘superstars’ on this graph aren’t all clustered together, nor are the busts. The main takeaway is that WAR does generally go down when strikeout rate goes up, and vice-versa.  Based on this data, things go rather poorly (outside of a couple of players) once you get over a 25% strikeout rate.  In other words, it’s not a good idea to go all-in on a prospect with that kind of strikeout rate.

One fact worth mentioning is that a lot of the players that flamed out in the big leagues spent much of their later career in the minors, naturally seeing their strikeout rate decrease as they grew more accustomed to the high minors.  So, these results may be a bit understated.  Still, it’s unlikely the data would have been significantly stronger had I only looked at strikeout rates from their ‘prospect days.’

Despite a lack of earth-shattering results, this knowledge can still be useful for dynasty leaguers when looking at top prospects.  It is important to keep in mind that some profiles, such as big power bats, are more likely to succeed with a higher strikeout rate.  In other words, Miguel Sano’s 26% strikeout rate isn’t nearly as worrisome as Trevor Story’s 30.6% mark.  In addition, some players’ high strikeout percentages can be partly dismissed due to age: prospects being challenged at a younger age than most can lead to inflated strikeout rates that aren’t as concerning. For example, Joey Gallo and his 34.7% strikeout rate isn’t as bad when taking into context his power profile and age, though that doesn’t mean he’s out of the woods.  Gallo’s not a bad prospect to own, but trading a hefty sum for him in a dynasty league is unwise given the higher chance he busts due to strikeout rate.  As a general rule, it’s fine to own some of these prospects that have a lot of swing in miss in their game, but those with high strikeout rates are best avoided in dynasty trades.

This strikeout and performance correlation also exists at the big league level; players with a strikeout rate in the majors over 30% have generally struggled. Outliers exist, like Chris Davis, but the majority of high strikeout bats have had trouble sustaining long-term success.  Big power profiles do have a better chance of succeeding with a large strikeout rate, but it’s still never a good sign. Rarely can you find a big leaguer sustain success with a strikeout percentage north of 30%.  Although they won’t kill a player, putting all your eggs in the basket of that type of prospect is something dynasty leaguers should try to avoid.