One of the themes for great teams remaining great is their ability to develop from within and find success stories on the margins.

Perhaps no team has encapsulated that theme as much as the Astros over the last half-decade. Acquiring and developing Yordan Alvarez, Kyle Tucker and Jose Altuve into the superstars that they are is a good start. What takes Houston to the next level, though, is building around their stars with continuing player development success.

Even as players like Carlos Correa and George Springer change teams, and they miss on free agents like José Abreu, they're able to withstand it by finding key role players. In 2023, that's come in the form of Chas McCormick, J.P. France, Yainer Diaz and Mauricio Dubón.

It's McCormick who's been the best of that bunch and has emerged as one of the most important players for an Astros team that finds itself in a tight race for its seventh consecutive playoff appearance. How did this former 21st-round pick out of Division II Millersville University and unheralded prospect make the ascent to this level? Here's how.

All stats are through Saturday's games

Few have been as good on a per-game basis in 2023

Despite playing in just 89 games -- he missed time on the injured list with a back issue -- McCormick has been one of the best players in the Majors when he's been out there. Seriously.

McCormick has accumulated 3.7 fWAR, tied for 28th among position players, just behind names such as Fernando Tatis Jr. and Juan Soto. His 144 wRC+ is tied for 12th-best (min. 300 plate appearances), ahead of players like Bryce Harper and Corbin Carroll. The 28-year-old is getting on base at a .366 clip and slugging .521, giving him a multi-pronged approach to success.

What's most impressive is that, on a game-by-game basis, McCormick has been one of the most valuable players in baseball.

Highest WAR, fewer than 100 games, 2023
1. Corey Seager (TEX): 5.0 WAR, 87 games
2. Sean Murphy (ATL): 4.3 WAR, 91 games
3. Cody Bellinger (CHC): 4.0 WAR, 99 games
4. Chas McCormick (HOU): 3.7 WAR, 89 games
5. Aaron Judge (NYY): 3.6 WAR, 76 games

McCormick has enhanced his strengths even more

Prior to this season, McCormick carved out a prominent role with Houston as a strong defender and a right-handed bat that could mash lefties and crush the fastball. He's taken that motto to another level at the plate this season.

From 2021-22, McCormick posted a .298/.371/.536 line in 205 plate appearances against left-handed pitchers. His 153 wRC+ against southpaws was bested by only 13 hitters (min. 200 plate appearances). This year, McCormick has been the third-best hitter in the Majors against lefties.

Highest wRC+ vs. LHP, 2023
Min. 100 plate appearances.
1. Mookie Betts (LAD): 200
2. Ryan Mountcastle (BAL): 196
3. Chas McCormick (HOU): 189
4. Freddie Freeman (LAD): 188
5. Jorge Soler (MIA): 186

On top of crushing lefties at an astonishing .340/.407/.649 clip, McCormick is also doing major damage against fastballs, especially four-seamers. Against four-seamers last season, he slugged .648 and had a +16 Run Value -- an assigned value based on the outcome of each pitch (ball, strike, home run, etc.).

This year, only one hitter has produced more value against a single pitch type than McCormick has against four-seam fastballs.

Highest Run Value against single pitch type, 2023
1. Freddie Freeman (LAD): +22 vs. four-seamers
2. Chas McCormick (HOU): +21 vs. four-seamers
3. Shohei Ohtani (LAA): +20 vs. four-seamers
4-T. Kyle Tucker (HOU): +18 vs. four-seamers
4-T. Jeimer Candelario (CHC): +18 vs. four-seamers

He's cleaned up his weaknesses

What makes McCormick's ascension so impressive is that he didn't just take his strengths to another level but he also improved some of the weaknesses that were holding him back.

In his first two seasons, McCormick hit .232/.308/.381 with a 95 wRC+ against right-handed pitchers. Given his strong defense, that was enough to make him a viable starter against same-side pitching but not enough to raise his ceiling. That script has flipped this season.

McCormick vs. RHP: 2021-22 vs. ‘23
wRC+: 95 // 122
BA: .232 // .250
OBP: .308 // .344
SLG: .381 // .458
xwOBA: .308 // .336

Another area McCormick has drastically improved in each MLB season is success against pitches on the edge of the strike zone. As a rookie in 2021, he slugged .322 with a .243 wOBA against edge pitches. Last season, those numbers jumped to a .493 SLG and .339 wOBA. McCormick improved even more this season to the tune of a .528 SLG and .343 wOBA.

That success has been especially noticeable on pitches on the inner half of the plate. After hitting a combined two home runs on inner-third pitches from 2021-22, he's homered four times on those pitches this season. Whereas he slugged .384 against inner-third pitches in his first two seasons, he's slugging .625 against them this season.

Part of that success on inner-third pitches has derived from his ability to pull more baseballs for power. McCormick's 14% increase in pull rate is the highest among qualified hitters. That, in turn, has led to a .717 SLG on pulled batted balls, a drastic increase over his .493 SLG last season.

Like many successful right-handed Astros hitters -- Altuve and Bregman are obvious examples -- McCormick is using his pull power to take advantage of the Crawford Boxes that are only 315 feet away at Minute Maid Park.

The long-term outlook

Like any player enjoying a great season, McCormick has caught some breaks along the way.

His .350 expected wOBA -- based on the quality of contact (exit velo, launch angle), strikeouts and walks -- is 27 points lower than his .377 wOBA. Only 19 hitters have a higher positive difference between those two numbers. He's also running a .345 BABIP and 22.9% home run/fly-ball rate, both of which are top-25 marks (min. 300 PA). Add in a 20th percentile strikeout rate and 22nd percentile whiff rate and there are at least some causes for concern.

Even if McCormick is playing a bit above his actual talent level, though, there are real signs that he's a legitimately good MLB hitter. That .350 xwOBA still places him as a borderline top-50 hitter, around names like Luis Robert Jr., Francisco Lindor and Justin Turner. With the positive changes he's made, there's good reason to believe that he's entered a new level and is a legit everyday player.

Is McCormick going to continue running a top-20 wRC+ and play at a 5-WAR clip? Probably not. Is he a potential 4-plus WAR player who can play every day for the Astros? The answer to that question is looking like a resounding yes.