They Grow Up So Fast

We didn't invent tempo-free stats. Neither did John Gasaway, Ken Pomeroy, or even Dean Oliver. Best we can tell, some guy who won a few games in North Carolina did. The fact that tempo-free stats aren't new should not come as a surprise. They're not terribly difficult to understand, and most are pretty easy to calculate as well. And moreover, they seem to illuminate productive basketball moreso than the traditional "per game" stats. So of course coaches (who tend to understand basketball pretty well) know about these things. Maybe that's why the tempo-free revolution that was to be televised has been met with a collective "ho hum" from the industry. Some of these stats already litter your local head coaching office, and probably did before Dean Oliver ever wrote his book. And this nugget, which I hope to illustrate in this post, is already something very well-known among coaches:

_"The best thing about freshmen is that they become sophomores." _

Al McGuire said that, and he was absolutely correct. As much as freshmen titillate with potential, they spend even more time frustrating coaches with uneven play. Freshmen commit more turnovers, miss more shots, are more timid in the offense, rebound less, etc. In general, freshmen are the worst class of player in college basketball.

But everyone reading this blog already knows that. The more interesting question is how much further back are freshmen relative to sophomores, juniors, and seniors. Or, put differently, how much we can expect freshmen to improve as sophomores? And how much we can expect sophomores to improve as juniors? And so forth with juniors to seniors.

And that's how I spent my summer (ok, I had an intern helping. And by "intern" I mean "college-aged family member who slept on my couch all summer.") -- looking at the statistical profiles of every BCS conference player who first stepped on campus between 2000 and 2005 (i.e., the last group's senior year was last season), with some additional filters:

No players with less than 10% Minute Percentage as a Freshman: In this study, the freshman year is the baseline number. We're measuring change, and that measurement is no good if you can't get a reliable relative point. Ten percent is arbitrary, admittedly.

Omit successive years with less than 10% Minute Percentage: Again, I didn't want small samples polluting the data.

Omit one-and-done players: Again, the measurement is change. A player has to give me at least one change data point to be considered.

No transfers: By and large, transfers not only change schools, but significantly, levels of competition. The most common transfer was from a BCS school to a low-level conference school. When the numbers improve, it's impossible to separate player development from the change in the competition level.

Conference games only: My affinity for conference game numbers is well-documented in this space. The idea is to try our best to hold the level of competition constant.

Results

The big, overarching conclusion is this: a player shows the most improvement between his freshman and sophomore seasons than he does any other offseason. In fact, the freshman offseason improvement is, on average, greater than the improvement between a player's sophomore season and his senior season. That's not to say every player follows this pattern. There are lots and lots of exceptions, and this is no hard-and-fast rule. It's just a remark about the averages. And frankly, that's all we do around here, play the averages.

Pretty graphs below (going left-to-right is freshmen to sophomore to junior to senior):

The pattern is clear in all of the graphs, and perhaps most striking in the Shot% and TO% graphs, where a logarithmic growth & decline are shown (Keep in mind, this doesn't contradict Pomeroy's earlier work on shot percentage - that range is showing a pretty narrow band between 18% and 20.2%).

And now, to bring on home to why our readers should care. For that, I bring you the 2008-09 Fighting Illini. This team won 24 games after going 16-19 the year before. Yes, a lot of that was bad luck (or "bad DeChellis" if you prefer), but the Illini also lost 1/3 of the minutes from that 16-19 team. It's not like everyone came back. Another key piece in the Illini's resurgence is that 48% of the minutes were played by sophomores. In other words, 48% of the minutes were played by guys who figured to improve the most. And they did.

So what does that mean for this season? Well, nothing definitive, but we have started factoring this into our analysis of the teams for this season. And this graph should prove handy for others who want to do so as well:

_(Note: In this table, I counted Alex Legion as a sophomore for the upcoming season, even though that's not technically accurate. Laval Lucas-Perry played in 5 games at Arizona, Legion played in 6 at Kentucky. It didn't make sense to treat them differently.) _

As the graph shows, Illinois figures to be at the other end of the spectrum this season. Not surprisingly, Indiana laps the field. And maybe the people ranking Michigan and Minnesota (#15 and #18, respectively, in the initial coaches' poll) aren't so crazy after all.