Fantasy Baseball: The Hot Start / Cold Start Effect

San Diego Padres first baseman Yonder Alonso slides into second base. Mandatory Credit: Christopher Hanewinckel-USA TODAY Sports

As the Padres offense suffers through one of the worst starts in team history, our thoughts perhaps drift a little more toward our fantasy baseball teams.  If the Padres can’t hit, at least my fantasy team, the Omaha Omahogs, can.

At this time in the fantasy baseball season, we’ve seen about 100 ABs from most starting players.  There are some players who went undrafted who are in the top tier of players (e.g., Charlie Blackmon).  And there are some high round draft picks (e.g., Allen Craig) who are really stinking up the joint.

How much attention should we pay to these starts? At what point do we cut Clay Buchholz loose and pick up Jason Vargas?

At times like these, we must consider the “hot start / cold start effect”.  Here’s an example.

At the beginning of the season:

Player A gets off to a hot start over the first 30 games, going 35 for his first 100, for a .350 average. Let’s say it’s Adam LaRoche.
Player B gets off to a terrible start, going 15 for his first 100, hitting .150. Let’s say it’s Yonder Alonso.

After his hot 4-week start, LaRoche cools off significantly, hitting a slightly-above-average .273 for the remaining five months of the season, encompassing 440 ABs. Alonso shakes off his slump and then stays hot, hitting an excellent .314 over his next 440 ABs.

Without doing the math, who do you think has a higher average at the end of the year?

LaRoche ends up with a slightly higher average, .287 to .283, yet would likely be perceived as having a much better year for almost the entirety of the season. Which is interesting, because Alonso was clearly more productive for more than 80% of the season.

To show how a very hot or very cold start can affect perception throughout the entire season, let’s look at their batting averages at various points in the season. (We’ll assume, for the sake of this example, that LaRoche hits exactly .273 over each period after the hot start, and Alonso hits exactly .314 in each period.)

The initial 100 AB
LaRoche .350
Alonso .150
.
160 ABs (heading into Memorial Day weekend)
LaRoche .321
Alonso .212
.
270 AB (half-way point of season)
LaRoche .302
Alonso .253
.
360 AB (beginning of August – 260 ABs since the hot/cold start)
LaRoche .294
Alonso .268
.
450 AB (Start of September)
LaRoche .290
Alonso .278
.
540 AB, end of season
LaRoche .287
Alonso .284
.
If we only look at the stat sheet at the end of the season, we don’t know what happened during the course of the season; we only see the final numbers. So we think their seasons were quite similar. And overall, they were, with LaRoche ending up with 155 hits to Alonso’s 153.

But the people who followed the stats during the season might say LaRoche had a great year, hitting around .300 for most of the year, and only slumping at the end. And Alonso managed to salvage his horrendous season with a decent second half. The perception is completely different.

So, to the other owners in my fantasy league, I say enjoy the hot starts of Nelson Cruz, Dee Gordon, Matt Wieters, and Alexei Ramirez. They are having great years. You will never need to worry about whether to replace them or not. Isn’t that a nice feeling?