After looking at September breakouts for both power and speed, it's time to finish our series by looking at a few guys who saw real batting average spikes during the season's final month.

Now, batting averages are often most impacted by hot streaks and lucky stretches, but by looking under the surface and picking apart the Statcast and batted ball metrics, it's a little bit easier to see if there is anything reliable that indicate legitimate growth. While a 25+ game sample size isn't the largest, it does provide more than 100 plate appearances and enough time for certain metrics to stabilize.

As a result, all four names on this list are guys who I believe can be useful to fantasy teams in 2020. I'm just not buying all of them at the peak they showed during September.

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September stats: .347/.400/.566 4 HR, 9 RBI, 21 R, 1 SB

Tim Anderson neither saw an increase in steals or home runs during September, but his average during the month was the cherry on top of a 2nd half that saw him hit .357/.376/.529 with seven home runs, 19 RBI, and 42 runs. What immediately stands out is the mercurial nature of Anderson's xBA over the course of 2019. This is the epitome of streaky.

Even though his average rose in the second half of the season, he still experienced massive fluctuation and the season ended with a clear downturn in xBA despite the results that would have suggested otherwise. To pile on, his 8.4-degree launch angle decreased from 2019, and his 88.3 mph exit velocity is fine, but together they don't scream 20 home-run bat.

Plus, his xwOBA (pictured right) was below league average for much of the second half of the season and doesn't inspire much confidence in the breakout, as the .328 number for the season isn't particularly strong.

As one positive, Anderson's 4.18 home-to-first time was good for 58th in the league, tied with Amed Rosario and ahead of Ronald Acuna Jr., so the speed is legitimate enough to make a 20 stolen base year plausible again if the White Sox run him more. This means that Anderson's peak may be what we've already seen: a 20-20 threat with solid runs totals, who will hit around .250. It's fine, but I'm not sure I'm drafting that over Marcus Semien if I don't need the stolen bases, and I'm not entirely sure it's not smarter to just wait for Rosario or Elvis Andrus since Anderson could also settle in around 15-15 instead of 20-20.

September stats: .412/.455/.647 3 HR, 15 RBI, 21 R, 3 SB

A batting average breakout that I'm more interested in is Anderson's teammate, Yoan Moncada, who showed impressive growth in his average and power with a career-high in home runs and ISO. What's more, a look at the underlying metrics suggests that, despite his breakout and the tremendous September stats, Moncada actually wore down at the end of the season.

Moncada's average was influenced by a ridiculous .406 BABIP, but his .291 xBA is still useful in fantasy leagues. However, despite his increase in barrels, his launch angle decreased from 15.1-degrees to 12 on the season. Much of that occurred at the end of the season when many of his metrics seemed to nosedive after around September 13th.

Moncada spent the first three weeks of August on the injured list with a hamstring injury, so his body may simply have been wearing down at the end of a long season. He was listed as injured five times during the 2019 season, twice with back injuries and three times with various leg ailments. While he still was able to play in 132 games, it's possible that the impact of those injuries had taken a toll on his body since not only did his launch angle plummet at the end of his season but his K% (pictured left) skyrocketed and his BB% (pictured below) fell drastically. All of which suggests that his comfort level and entire approach at the plate was off.

What this all says to me is that Moncada's strong September could have been even better and the overall decrease in launch angle was affected by wear and tear. His average launch angle rested comfortably between 13 and 14.2 from June 10th to September 6th, until dropping with the rest of his metrics. If Moncada is able to play a full healthy season, we could see final numbers close to .280 with 25+ home runs and 15 stolen bases.

September stats: .341/.419/.681 6 HR, 19 RBI, 17 R, 1 SB

I've never been incredibly high on Schwarber in the past. I thought that his defense was too poor to allow him to play consistently and he'd wind up being a slightly above-average bat that didn't hit for enough power to truly prove useful in an age of superfluous power. However, his batting profile has become a bit more enticing of late.

While Schwarber only walked 11.5% of the time last year, he has a 13% career rate, and his power growth appears to be real. His .375 xwOBA was 30th in the league, and his .553 xSLG was 20th best. What's more, his xBA, xSLG, and xwOBA were all higher than his actual results, which suggests he may have more room for growth in his power numbers. That's a train of thought that's backed up by 97th percentile exit velocity and 99th percentile hard-hit%. At only 26-years-old, he might only be scratching the surface of his true talent as a hitter.

He's clearly a good bet for 30+ home runs, but the plate discipline and improved quality of contact hint at growth in batting average that might be more important for fantasy owners. I see no reason why Schwarber can't become a consistent .250- .260 hitter who can contribute solid counting stats in the middle of a good lineup. After all, look at all that red below (as long as we don't focus on defensive metrics).

September stats: .365/.433/.615 6 HR, 23 RBI, 17 R

After Mancini had surgery to remove a malignant tumor from his colon, I figured it was time that we focus our attention back on his talent as a baseball player (while obviously wishing him the best in his recovery). Mancini's first and second half split look eerily similar based on a hot month of April and a scorching month of September. While there were some down months in between, I think September is a good indication of the ceiling we find in the 28-year-old.

Mancini dropped his K% down to 20.8% while raising his BB% to 9.2%. While the average was propped up by a .427 BABIP, Mancini was making consistently strong contact at the end of the season, as indicated by the clear xBA improvements (left). His launch angle, which had dropped considerably during the month of August, picked back up and climbed to just under league average in September while his Hard Hit% spiked from September 3rd on, remaining above 40% for almost the entire remainder of the month.

Based on his underlying metrics for the whole season, it seems that the batting average growth is real, and Mancini can be counted on for a .270 or higher average, but he's going to need to keep his launch angle up if the power numbers are going to be repeated. He plays in a hitter's park, which will always help his home run total, but a 7.8-degree launch angle usually doesn't lead to consistent 30+ home run seasons. His spike at the end of the year was helpful, but he's going to need to show that more consistently if we're going to buy into him as a 30+ home run guy.

With the delayed start to the season, Mancini has a chance to recover and potentially get back out on the field. The surgery will impact his cardio and maybe strength as he begins to recover, but it shouldn't have any lasting impact on his skills. Let's hope that Trey gets a chance to show what he's capable of in 2020.