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Team Health Reports 2011 Primer

For nine years, I've been running a series I called the Team Health Reports. They've been described as being "read by fantasy leaguers and major-league GMs alike, the Team Health Reports are the most comprehensive and well-researched look at injury risk you'll find." That tradition continues this year here at SI Fantasy. It's a different venue, one where you'll get the best information around as part of our free package of fantasy tools, but continues the tradition. Many of you have prepped for drafts in the past, using every tool in the arsenal to put together a great list. You've probably had great drafts and then seen the whole thing go up in smoke as injuries took their toll on your team, forcing you to scramble for scrubs to fill out the roster.

I'll help you avoid that nightmare and more accurately value players, whether you're in an auction or a draft. There's two things that win in baseball and fantasy baseball -- talent and availability. The best team in the world can't win if it's players are on the DL. What the Team Health Reports do is assign a risk value to each starting player on the roster. To make it simple, those risks are banded together into three groups -- red, yellow, and green. The stoplight metaphor makes it very easy to grasp at a glance.

The System -- yes, it's capitalized -- has been tweaked this year and is more accurate and complete than ever. I've taken out a portion of the underlying equation that was projected and caused inaccuracies over the past two years, replacing it with playing time projections from Tom Tango's MARCEL system. In backtesting, this improved the accuracy of the 2010 numbers by 3 percent. There's also a new actuarial table underlying the system, which I'll refer to as the baseline. This table shows the actual incidence of injuries for players, broken down by position and age. I make further adjustments using 10 factors that have been shown to affect the risk of individual players and teams. No one else has that baseline and it's the real key to the system.

Red is, of course, the highest risk. Players in this band are coinflips -- they have a 51 percent or greater risk of having an injury, defined as something that will land that player on the DL. Remember, risk is probability, not destiny. A 51 percent risk means a 49 percent chance of health. In some cases, the player's reward will be worth the risk. Knowing that risk is part of having all the information. In other cases, you'll steer clear of players, finding ones of equal value and less risk.

Yellow is the middle risk, showing that a player has between a 30 percent and 50 percent risk of injury. Green is 29 percent and lower. These bands are slightly altered for this year, moving the low end of the yellow band down to better match the overall risk profile of baseball. Again, the baseline is the key here, and the slight reduction seen in MLB during the 2010 season is the reason for the change.

I've learned some lessons along the way that should help you in reading these reports and integrating them into your draft prep. I encourage you to not only look at the colors and ratings, but to read the comments in each team article. Sometimes, the system doesn't know things that my sources do. That's good and bad -- it doesn't get emotional about a favorite player, but it might miss an off-season surgery's effect or not grasp something like Javier Vazquez's innings drop last year. There are five key lessons to keep in mind:

History Repeats Itself: The term "injury prone" is thrown around a little too easily and sticks too long. An injury-prone player can be very valuable, but they have to be valued correctly. However, injury history is a key factor in the ratings. A player that's been injured in the past is more likely to have injuries in the future, especially among types of injuries that recur (like plantar fasciitis or arthritic changes in the knees) or can cascade (a pitcher with an elbow problem can often create a shoulder problem when they unconsciously change their mechanics.)

Jumps Lead to Falls: Tom Verducci has done amazing work over the years chronicling and bringing attention to the workloads of young pitchers. I coined the term "Verducci Effect" several years ago, though Tom modestly still calls it the "Year After Effect." It's common sense -- a young pitcher that hasn't made it over innings threshholds before shouldn't be overextended and fatigued. I wouldn't ask you to suddenly bench press 300 pounds or run a marathon. Pitchers, especially young ones, have to be worked up to levels. Research I've done in the past, in part with Nate Silver of, has shown that pitchers under the age of 24 are more likely to be injured due to increased workloads. Other research, including that done by Verducci, indicates that the jumps should come in 30 inning "hurdles." 130, 160, and 190 seem to be key numbers, especially the latter. While many will focus on the round number of 200 innings as the "ace level" in the modern five starter era, it's 190 that seems to be the last and toughest test.

Depth Counts But Isn't Shown: Few teams in the post-expansion era have much depth, especially in the starting rotation. One of the system's greatest weaknesses is that it doesn't understand platoon systems. This is especially problematic for catchers, but can be issues in other places. These kinds of situations are monitored more closely in the player comments on each team's reports. I'll have a comment for every yellow and red player, with comments on the more interesting greens, along with other information that will give you a better context for assesing the team and their medical staff. The other issue you'll get with depth and health is that it can't "see" the replacement. When Manny Ramirez was suspended and Juan Pierre had to step in, it was a perfect test case. There couldn't be a more disparate pair of players and yet, in the short term, the Dodgers didn't lose anything. Pierre played over his head for a couple weeks before settling back to his true talent level. This is something no one can predict. It's the beauty of baseball and why it's played on grass, not on paper. Depth is also the reason I don't try to project ratings for relievers. Aside from the ultra-elite, they're easily replaceable.

Age Matters, But Not Like You'd Think: Older players cost more in terms of the DL. That's a simple fact, but maybe too simple. If the populations were equal, you'd discover that things even out. The older players get hurt less -- a survivor effect -- but tend to take longer to heal. Younger players get hurt more, often in hustling, traumatic ways, but heal more quickly. It evens out over broad samples, especially when you consider there are more young players. Then again, there's always a Jamie Moyer or a Jason Heyward who pops up and throws off the extreme ends of the actuarial table! While it's good to know how age affects injuries, for fantasy purposes, you can almost throw it out. Don't be scared of young or old players just on age. It's one factor, but far from the most important one.

Vilfredo Pareto Was Not A Shortstop: Ever heard the saying that you need 20 percent of the stuff 80 percent of the time? For those of us with messy desks, we use that as an excuse, knowing that we can usually find the things we need at the top of the pile. Turns out, the rule is true in many ways. Whether you're talking about finding a file, the distribution of the world's wealth, or farming, that 80-20 rule shows up again and again. It has a name -- Pareto's rule, given for the Italian economist that first wrote about it in 1906, back when the Cubs were good. It has an application in baseball as well, since 20 oercent of the players account for 80 percent of the DL days and DL dollars lost. Medical staffs have to use this to decide how to best utilize their scarce time and resources. Knowing which teams have more than their share of red-level risks will help you decide which ones you want on your team.

Remember, the ratings you'll find in the Team Health Reports are a tool. Like any projection or prognostication, they're a matter of probability. They're another piece of the puzzle, an information nugget that you can combine with all the other pieces you have collected and have learned to trust. As we start another baseball season, I wish each of you good luck and good health.