Sunday, April 11, 2010

Wells, Perception and the Hot Start

I don't want to repeat what I wrote in an extended essay back in May of 2005 so I'll begin by drawing an old article to the attention of newer readers via this link as it covered a lot of what I would be inclined to write today about the order of performances skewing perception.  In summary, that article was a presentation on just how the earlier stats can create confusion about how a player is actually performing during the current season.

Turning our attention to 2010 or if you're not interested in reading that extended essay, there is no more serious a time to apply the "buy low, sell high" mentality than early in the season.  It's incredible how much a player like Vernon Wells has boosted his trade value with just one strong week.  If he had hit four home runs in a week in, say, June, we'd be talking about a hot streak.  When you hit four home runs in the first week, suddenly the general population is armed only with that performance to analyze your current ability and speculates you're Babe Ruth.

Of course, it wouldn't be fair to pick on Wells for having a strong and well-earned start to the season.  He had wrist surgery during the off-season that may have lifted his power back up somewhat compared to how it appeared last year.  In fact, we are expecting his power to be a bit better this year than last year as we're currently projecting a home run about every 30 times he puts a ball in play compared to about every 36 times last year.  But we weren't projecting anything close to what he's done this week.

On that note, we have to remind ourselves of other great starts in baseball history that are comparable.  In particular, I am drawn to the three home run opening day performances of George Bell and Karl Rhodes, Bell in 1988 and Rhodes in 1994.  For what it's worth, Bell went on to hit only 21 more the rest of the way that year and Rhodes hit - wait for it - just 5 more home runs after that strong opening day, even though he managed to finish with 269 at bats that year.

The extended essay I linked to in the first paragraph reminds us that just because a player starts hot does not mean that he's bound to have a balancing cold streak later.   It's that we just have to keep year-to-date stats in perspective and remember that one week rarely, if ever, reveals a complete change in ability.  It can happen but it would take something extraordinary.  For example, when Kerry Wood struck out 20 Astros in 1998 in a single game without walking a batter, whatever limited doubt I may have still had about his readiness for the majors was instantly removed.  A game like that is not comparable to a more common shutout where a pitcher strikes out 10-12 batters, walks 2 or 3 and gives up a lot of ground balls.  The distinction is crucial if we're to recognize genuine readiness or change in a player's ability.

As there always is in April, there's an incredibly good opportunity right now and that is the potential to exploit a player's hot or cold start in your trade discussions.  A player like Vernon Wells is a great example of one who is now much more likely to hit 20 home runs than the 15 I was projecting a week ago, not necessarily because he's proving that he's a 20+ home run player but because he's already got a head start and even if he's only a 15 home run type player the rest of the way, he's already got four in the books.  Of course, when you're trading fantasy players, your focus should be on the portion of the season that hasn't yet been played.

Don't be afraid to deal away players out of fear that they're actually going to have a great season.  It can happen and when it does, you pick yourself up, tell yourself you got that one wrong but played the percentages and then move forward.  What you're interested in is long run ability and what is likely.  Let's continue with Vernon Wells.  He's thirty-one years old and to give him credit, he's been an exceptionally good sport given all the heat he's taken for a massive contract that's now in the $20+ million per year range, obviously anxious to prove his critics wrong.  But at his best in his career so far, he's had two seasons with more than 30 home runs and when he was in those best years, he was ranging between 23-33 before dropping back to the lower levels of 2007-2009, a great deal attributable to injury-shortened seasons.  Last year, he hit only 15 in 630 at bats.

Could Wells return to 30+ territory?  Sure.  Could he have a career year and hit 35-40 home runs?  Maybe. But in making fantasy transaction decisions for any player, consider the player's long run ability, the kind of ability you would bet on being the average if you played a billion seasons and averaged the outcomes of each.  If after analyzing the evidence of Wells' track record, including this excellent first week, you conclude that he's more likely to hit 15-20 home runs the rest of the way, well then now is the time to deal him if he's on your team.  Someone out there will salivate at the home runs so far and conclude that he's back to being what he was back in 2006 or maybe even better.  Perhaps he is but it's not a question of what he actually ends up doing as much as what he's likely to do that should motivate and inform our trading decisions, especially at this time of year.

In short, while it's possible that hot and cold starts reveal that a player is a completely different one than the one we saw last year, you have to remember that we're talking about one week of play when compared to entire still-recent full seasons of outcomes.  I don't remotely dispute that what a player has done more recently is a better indicator of his ability than what he did a long time ago but the great unknown is how much weight to apply to each.

On that note, let's consider the actual weight a little more.  Vernon Wells, as of this writing, had 17 at bats in the books this year.  Last year, he had 630 at bats.  Imagine that a player's real ability is comparable to a giant drum of marbles in which different colored marbles represent a different outcome.  Throughout his career, the percentage of home run marbles in the drum is constantly changing as he gains experience, ages and of course, ultimately declines.  Now, last year we drew 630 times from the drum labeled "Vernon Wells" and pulled 15 home run marbles.  This year, we've pulled 17 times and have already pulled 4 home runs.  How much faith are you going to put in those 17 recent draws and how much will you put in last year's 630 draws?  Can we conclude that the marbles in this year's drum are made up of an entirely different proportion than last year's based on those 17 draws made this week?  Ultimately, each of us has to decide this for ourself in the context of our comfort level and confidence.  I personally try to do this as we adjust our forecasts throughout the season and certainly, by the third or fourth week of April, a player's start does begin to significantly affect the forecasts.

For now, you've got an opportunity to account for an unexpected start without over-weighing it in your trade discussions.  Above all, never be afraid to get individual decisions wrong as long as you're always thinking about the long run and your average outcomes.  I've seen players lose their league because they were afraid that a player was about to have a career year and thus, didn't want to trade for him after a hot start.  Perhaps they fear acquiring a player like Javier Vazquez, who just had one of his worst starts in a couple of years, because they think one terrible start represents something wrong with the player.  Sure, it can happen.  If you traded for Chien-Ming Wang after last year's miserable beginning to the season, you got burned even more after he never recovered from it.

But remember that fantasy baseball and winning is about playing the percentages and accepting that by the nature of that, there will be times you get it wrong.  The key is to always be putting the odds in your favor and taking advantage of the far too heavy weight that some others put into April stats.  No doubt, some players really will be revealing entirely new abilities this month.  In the long run, though, when it comes to veterans with strong job security, the first week is just another week, April is just another month and Vernon Wells is not likely to become Ryan Howard.