Should fantasy owners care when a player switches leagues?

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The American League and the National League not only have different rules, but the game's are different, the pitching is different and the ballparks are different. Significant fantasy implications come from a player switching leagues -- for better and for worse. So yes, you need to take notice when a player switches leagues.

Here is a deeper look at how the two leagues differ:

AL ballparks are more hitter friendly

*Park Factors courtesy ESPN. A rate higher than 1.000 favors the hitter. Below 1.000 favors the pitcher.

Aside from the anomaly of 2014, the AL park factor has been considerably better over the past four seasons. This also takes into consideration Colorado's Coors Field which has the highest park factor virtually every season, therefore spiking the NL's overall number.

The AL's park factor is driven mostly from the AL East. Yankee Stadium, Fenway Park, Rogers Centre and Oriole Park at Camden Yards are all bandboxes which perennially house dominant lineups.

A longtime successful NL pitcher could struggle with a move to the AL. Take RHP Jake Peavy, for example. He dominated with the San Diego Padres, largely underachieved with both the Chicago White Sox and Boston Red Sox, but was able to rejuvenate his career with the San Francisco Giants.

Power hitters moving from the NL to the AL should enjoy more success in their new home but it is far from a guarantee.

NL pitchers throw more fastballs

Though the smaller ballparks represent a massive advantage for hitters moving to the AL, they could wind up struggling if they have trouble laying off breaking balls. As you can see above, offspeed pitches are relied upon more heavily in the AL.

Consider the cautionary tale of White Sox 1B/3B Todd Frazier. Sure, Frazier slugged out a career-high 40 homers in his first year with the White Sox, but his batting average, OBP and OPS all dipped from the two seasons prior.

From 2014-15 with the Reds, Frazier saw 54.1 percent fastballs and his average pitch value (how successful a hitter was against a certain pitch; zero is average) against the heater was 20.25. This past season he saw only 52.9 percent fastballs and his fastball pitch value was 10.8 -- nearly half of what it was the previous two seasons. This explains why he set a career-high in strikeouts.

Who switched leagues this offseason?

*Matt Moore was moved from Tampa Bay to San Francisco at last year's trade deadline.

As you can see from the table above, a pitcher from AL to NL doesn't necessarily improve fantasy value, while a hitter going from the AL to the NL doesn't necessarily decrease fantasy value. Other factors need to be taken into consideration.

Ramos: His fantasy value is hindered by starting the season on the DL, but once healthy, he should be able to mash in the AL East, even though his home ballpark is fairly neutral.

Segura: The elevation of Arizona and the smaller Chase Field were major factors for his power surge last season. Don't expect the power numbers in Seattle, but plenty of steals and a healthy amount of runs scored will stabilize his value, even if he hits only .280.

Eaton: Eaton spent the first two seasons of his career with Arizona, so the NL won't be completely unfamiliar to him. He will enjoy hitting atop a lineup featuring 2B/OF Trea Turner, 1B/2B Daniel Murphy and OF Bryce Harper.

Hammel: Hammel has spent six years in each league throughout his career. His career NL ERA is 4.15, while his career AL ERA is 4.90. It's worth noting he pitched three of those NL years for the Rockies. His HR/9 spiked each of the last two seasons while pitching with the Cubs. I wouldn't go near him with a 10-foot pole this season.

Dickey: Dickey should provide solid late-round value with a move back to the NL, where is inability to keep the ball in the yard will be somewhat hidden. His upside is limited, but he should log 200 innings with an ERA between 3.50-4.00.

Walker: The Diamondbacks not only play in a hitter-friendly stadium, but they were also one of the worst defensive teams a year ago. Walker's breakout season might be a couple years away.

Moore: In 21 starts with the Rays last season, Moore's HR/9 was 1.40. In 12 starts with the Giants it was 0.70. Though his ERA stayed the same, his FIP was nearly a run lower. He should have a great year moving from the AL East to AT&T Park, one of the most pitcher-friendly stadiums in baseball.

(Photos courtesy Action Images)