Father & Son, Guerreros’ slumps in September

Like father, like son! Vladimir Guerrero and Vladimir Guerrero Jr. both hit double-digit home runs in their first full MLB season. When I looked these 2 great batters’ first season. Both were not bad, Guerrero’s BA and OPS are better than his son. Guerrero Jr. accumulated more home runs and RBIs.

Vladimir Guerrero (1997*)		Vladimir Guerrero Jr. (2019)
.302	BA	.272
40	RBI	69
11	HR	15
.833	OPS	.772

*Vladimir Guerrero played only 9 games in 1996

Compared to his dad, Vladimir Guerrero Jr. had a higher batting average post all-star. We saw Guerrero’s BA declined in August, but it was still fine. However, “Dos Guerreros” slumped in September.

Vladimir Guerrero (1997)		Vladimir Guerrero Jr. (2019)
.323	BA (Pre All-Star)	.249
.278	BA (Post All-Star)	.293
.390	BA (Jul.)	.284
.275	BA (Aug.)	.341
.216	BA (Sep.)	.232

To understand this situation, I looked at Guerrero Jr.’s statcast data last season.

EXIT VELOCITY (mph)

Guerrero Jr.’s exit velocity dropped a lot after having played well in August.

HARD HIT (%)

Guerrero Jr.’s Hard Hit% declined, particularly against offspeed.

SWING (%)

He swung more often than he did in July or August, especially at offspeed pitches.

IN ZONE SWING %

Guerrero swung less in zone fastballs in September, but against breaking balls and offspeed pitches, he basically just swung.

IN ZONE SWING & MISS (%)

He also missed in zone fastballs and breaking balls in September.

CHASE (%)

In addition, he chased more in September.

From data above, we shall see that Vladimir Guerrero Jr. might probably lose some disciplines when at bat in September. The hard hit% declined dramatically because he chose to swing more against breaking balls and offspeed pitches. Meanwhile, even in zone fastballs, he missed more than he did in July or August.

Well, Vladimir Guerrero Jr. might be fatigued in September and in that situation, he can't perform at the same level as he did in August. The team’s top prospect and fans expected him to play like an All-Star. He too aggressively wanted to perform well and his shape might also be a problem, he was overweight, that might cause fatigue. However, players have ups and downs in a season and it’s also quite often to see rookies get exhausted at the end of the first full season. The good news for Vladimir Guerrero Jr. is that the solution/answer to overcome is probably just “at home” and he can find it easily.

Will he find it? Another great Guerrero’s story? Let’s see.