Up and down starts: A look at sustainability

Last week we featured standout numbers from the first month-plus of the Minor League season and how we're beginning to get out of small-sample-size territory. We also posed the question, "Are any early-season numbers definitive? Of course not." Let's expound on that.

There are a couple of MLB.com's top 100 overall prospects who have gotten off to incredibly good or incredibly poor starts based on traditional stats such as batting average and ERA. But dig a little deeper into the peripherals and you'll realize that things may get much better -- or worse -- as the season progresses and "luck" turns around. We've talked about prospects like Rafael Devers and Dan Vogelbach's unsustainable starts in recent daily roundups. Below is a closer look at five others.

(Note: All stats are through Monday's games, unless otherwise noted.)

Rockies RHP Jeff Hoffman, No. 48 overall, Triple-A Albuquerque: By usual standards, Hoffman's first full season in the Rockies system is off to a great start as he's gone 2-1 with a 1.96 ERA. Go a little deeper, and that's when things start to look a little less rosy. Hoffman's put up a fairly average 7.4 K/9 over his six starts (36 2/3 innings) with the Isotopes, and that, combined with a relatively high 1.0 HR/9, leads to a rough 4.53 FIP. No pitcher in the PCL has a bigger gulf between his ERA and FIP than Hoffman's 2.56. A big part of that is Hoffman is fairly contact-reliant as a groundball pitcher, and if his defense can help keep his batting average on balls in play (BABIP) low, then the ERA should follow. Hoffman's .228 BABIP is second-lowest in the PCL, and while Hoffman's ability to limit extremely hard contact in the early going is laudable, until he starts missing bats at impressive levels, don't get too caught up in thinking he's been especially dominant based on ERA alone just yet.

Cardinals RHP Jack Flaherty, No. 76 overall, Class A Advanced Palm Beach: It's the opposite issue for Flaherty, who hasn't taken kindly to the Florida State League so far. The 20-year-old right-hander is 0-3 with a 6.08 ERA and 1.61 WHIP through six starts (26 2/3 innings) with Palm Beach, and that could be potentially worrisome if it were over a larger sample. However, there are still reasons for optimism when it comes to the 2014 first-rounder. First, let's set aside but acknowledge that seven of his 18 earned runs came in one disastrous April 19 outing that lasted just 1/3 of an inning, Second, consider that he's still striking out 9.1 batters per nine innings and has posted a fairly solid 3.48 FIP. If you took those two numbers alone, you'd think Flaherty was off to an OK start. Instead, he's hurt by a .372 BABIP and a low 59.7 percent left-on-base percentage. Those stats were at much more normal levels at .331 and 72.3 last season at Class A Peoria, where he had a 2.84 ERA and 2.83 FIP. If there is anything worrisome with Flaherty, it's that his control is hurting him as his BB/9 has jumped from 2.9 in 2015 to 4.1 in 2016, but expect better numbers from St. Louis' No. 2 overall prospect going forward. 

A's 1B Matt Olson, No. 96 overall, Triple-A Nashville: Turning our attention to hitters, Olson hasn't exactly hit the ground running in his first season at the Triple-A level with a .167 average and .591 OPS through 28 games. But it gets better from there. He's still the same Olson of years past in that he's taking plenty of walks, namely one in every 14 plate appearances. That's led to a .280 OBP that seems palatable next to his average. What's more, even that stat should improve going forward as the A's prospect's .211 BABIP is third-lowest among all PCL batters. Consider this: when Olson hit .249 last season at Double-A Midland, he had a .311 BABIP. So that average should rise significantly, even if it never gets all that high, and his OBP should look even more impressive as it makes the turn for the mid-.300s. The next thing that'll need to come is his plus power, typically seen as his best tool. The 22-year-old has gone deep just three times and owns a fairly pedestrian .144 ISO, down from .189 in the Texas League. If he can't provide some pop, it may not matter how much of an excuse he has for his lower average.

Astros 1B A.J. Reed, No. 36 overall, Triple-A Fresno: Reed is in a similar situation to Olson, albeit not as extreme a case. The Astros' No. 2 prospect is hitting just .223 over his first 27 games in the PCL, one year after he hit .340 at two levels in his breakout first full season in the Houston system. The peripherals, however, are much rosier. His 20.8 strikeout rate is almost identical to his numbers at Double-A (20.7) in 2015, while his walk rate has jumped from 11.4 to 13.3, leading to a more respectable .325 OBP. What's more, he's still bringing some decent power with six homers and a .233 ISO. The whole package has resulted in an above-average 111 wRC+, despite the low average that is hurt by a .233 BABIP, a number that should rebound as the summer progresses. If you need more convincing: Reed hit just .208 during the first month of the 2015 campaign with Class A Advanced Lancaster, and that was with a much more helpful .261 BABIP. You know how that ended, so Reed should be fine.

Pirates C Reese McGuire, No. 94 overall, Double-A Altoona: McGuire has always been considered a defense-first catcher, so whatever offense he can bring in the Pittsburgh system is generally a bonus. The problem is there hasn't been that much of it in the early going in the Eastern League. The 21-year-old backstop is hitting just .222 through 21 games, and even with the 16 hits he has collected, only two have gone for extra bases (one homer, one double). He's run into same bad luck at least in the first department, though, with just a .234 BABIP. The news gets even better from there as McGuire's walk total (14) is double his strikeout total (seven) through 86 plate appearances. That knowledge of the strike zone -- perhaps unsurprising for someone who makes a living behind the plate -- has led to a salvageable 92 wRC+, and that number should rise as BABIP normalizes.