What are the make or break years for major-leaguers? While there is obviously no 100% rule that applies to every player, a good rule of thumb is 3/15/25. Come again? What I mean is that players who compile at least 15 total WAR over three seasons, aged 23, 24 and 25, will usually have long and productive careers. But, those who don’t – well, not so much.

After the jump, I’ll explain further and preview some of the current breed of future stars.

Since 1901. there have been 82 batters who have compiled 15 WAR in their age 23, 24 and 25 seasons. They range from Carl Yastrzemski, who was right on the bubble, to Mickey Mantle who more than doubled Yaz with 31.3 WAR. Of these 82 players, 62 (more than 75%) have gone on to compile at least 45 career WAR, comprising more than one-third of the 181 players to reach that career mark. Of the remaining twenty, eight are currently active, none of whom has yet reached 30 years of age. So, mathematically at least, all remain reasonably well positioned to reach the 45 career WAR total. Here are those active players, including those who have already passed the 45 WAR mark.

Outstanding group of players with several players either already well qualified for the HOF or who will clearly merit serious consideration for that honor.

If we lower the threshold just a bit, and look at players compiling 12 to 14.9 career WAR in those same 3 seasons, we get another similar sized group of 75 players. But only 33 players (44%) from this group have reached the 45 WAR mark. Of the remaining 42 players, only 8 are currently active, including two who have already reached age 30 and seem longshots to reach 45 WAR. Here are the active players from this second group, including those already at the 45 WAR mark.

Still good players, to be sure, but the overall quality is a notch or two lower. Probably only one with a very good HOF case right now, though there are a few others who are certainly not to be counted out just yet.

So now we have accounted for over half of the 181 players with over 45 career WAR. How many of the rest came from the next group of players with WAR of 10 to 11.9 in their age 23-25 seasons? Again, we have a similar sized group of 70 players, of whom 27 (39%) have reached 45 WAR. Of the other 43 players, only 5 are active, including one who has already reached 45 WAR and another who will do so in 2013.

Still some quality players here, including a couple on possible HOF trajectories. But, the declining number of players speaks to the fact that many players in the 10-12 WAR group will play themselves out of a career much sooner than those in the first two groups. In fact, of  the 70 players in the 10-12 WAR group, there are 39 retired players who did not reach 45 WAR and 23 who did not reach even 30 WAR.

So, who is left from the 181 players to compile 45 WAR? In fact, 52 of those 181 players (29%) failed to compile 10 WAR in their age 23-25 seasons. Those 52 players include the 21 HOFers below, so there is certainly still hope for the late bloomers.

However, the pool of players with less than 10 WAR in their age 23-25 season grows markedly. so the percentages are definitely not in a player’s favor. Here is what those chances look like, graphically.

The columns indicate the number of players compiling the indicated WAR totals in their age 23-25 seasons, partitioned between those who reached 45 career WAR (blue) and those who didn’t (orange). The green line indicates the percentage of those players reaching 45 career WAR. Note that the left vertical axis has a logarithmic scale.

As I said, the odds are against the crowd under 15 WAR, and grow really long below 10 WAR. Of course, nothing really surprising here except perhaps how few players do make a big splash early, and how long the odds are for stardom among the many who don’t.

Finally, I said I would mention coming attractions. The eagle-eyed will have spotted Andrew McCutchen in the first list as the lone 25 year-old from last season to join the 3/15/25 club. He is the latest of an impressive group of recent players with stellar seasons aged 23-25.

Not a bad way to start a century. And, quite the 5 year roll we’re on.

But, who should you watch for in 2013?

Oops. Looks like we’re into a little dry patch. But, not to worry. Look at those coming along after this group.

Ah – that’s more like it. And, even more impressive still are a couple of thoroughbreds following the bunch above. Let youth be served!