In the American League in 2011, you could project a team's BABIP -- its batting average on balls in play, that is, its AVG on everything except HR's, BB's, and K's, i.e., its AVG on balls that fielders had a chance to make a play on -- by adding 100 points to its line drive percentage. The league hit 19.6% line drives, and its BABIP was .295.
Fielders get to 70% of balls hit into fair play. Think about it and you'll see why this figure couldn't possibly be 90% or 50%. The earth is 70% covered by water, and the baseball field is 70% covered by defensive players.
This .300 AVG on balls in play is driven by the fact that ML teams hit 20% line drives. A team that hit nothing but screaming line drives would see about 75% of them go for base hits. Also known as Kevin Millwood Against Lefty Hitters The Other Day.
This can range up and down a bit. The A's, playing in their ballpark, added only 75 BABIP points to their line drive percentage in 2011 -- their LD's were 20.8%, and their BABIP .283. Only 75 points. That was the lowest gap in the league.
The feeble 2011 Mariners, playing in a bad park for BABIP and playing with bad hitters for generating offense of any kind, had 18.6% line drives and a .283 BABIP. The horrible offensive production still generated the normal 97-point gap between LD's and BABIP.
The woeful 2010 Mariners, the team that scored 513 runs, setting a DH-era record and in fact emulating a 1900's deadball offense, still had the usual 106-point gap. They hit 17.6% line drives but posted a .282 BABIP.
Some teams, of course, do better than that 10% gap. Last year, the Cardinals had a teamwide .337 BABIP, even with pitchers batting, and that was good for a 112-point difference. The Astros had a 117-point gap. etc.
The Mariners have a spectacular 24.3% line drive rate in 2012. That is easily the best line drive rate among 30 teams. But their BABIP is 27th in baseball. (No, fly ball rate and IF/F rate do not affect the conclusion significantly. The Mariners' "expected BABiP," broken down by GB's, IFF's, etc., is still vastly more than .265.)
The Mariners are hitting the best balls-in-play in the major leagues, period. They are getting close to the worst results on balls-in-play in the major leagues. Their BABIP is 22 (!!) points higher than their line drive rate. There is no way in heaven or earth that figure will be below 75 points at the end of the year; almost certainly it will be 90-110 by the end of the year.
The unluckiest individual Mariners? Miguel Olivo has a .176 line drive rate and a .176 BABIP. Heh!
Ichiro has a .259 line drive rate and a .264 BABIP. That's .005 points. For his career, Ichiro's spread is .148 points. Even last year, the disaster year, his spread was 104 points.
Michael Saunders has a .267 line drive rate and a .276 BABIP. There you go, Lonnie. With a normal amount of balls falling in for him, Saunders is a 300/400/500 hitter.
Justin Smoak's line is unpossible. He's got .289 line drives (!) and his BABIP is .278 -- he's got fewer balls hitting the ground between fielders than he has balls struck perfectly on the nose.
Seager isn't much better. His LD rate is .295 but his BABIP only .302. He's hitting a nice .292 with a .458 SLG, but it should be more like .370 with a .600 SLG. Also Dustin Ackley's BABIP is about the same as his LD rate.
There is one correct thing to tell the Mariners' hitters. GREAT job, men! Keep doing what you're doing. The breaks will even out pretty quick here.