A dinger gets you four, 5 letters
Air Force installations, 5 letters
Air-force units e.g., 5 letters
Bags at Camden Yard, 5 letters
Centers of operation, 5 letters
Corners of a diamond, 5 letters
Diamond quartet (and this puzzle's theme), 5 letters
First and second for example, 5 letters
First, second and third, 5 letters
First, second, third and home, 5 letters
Four at Camden Yards, 5 letters
Good politicians cover all of them, 5 letters
Military installations, 5 letters
Military operations centers, 5 letters
Points in a diamond, 5 letters
Political power centers, 5 letters
Runners may round them, 5 letters
Sometimes they're loaded, 5 letters
Stopping places when heading toward home, 5 letters
They may be loaded on the field, 5 letters
They may be stolen at Shea, 5 letters
They may get loaded at the baseball game, 5 letters
They may get loaded at Yankee Stadium, 5 letters
They might be loaded, 5 letters
They might be loaded at Shea, 5 letters
They might be stolen, 5 letters
They're 15 inches square, 5 letters
They're covered on diamonds, 5 letters
They're occasionally loaded, 5 letters
They're rounded on the way home, 5 letters
They're sometimes loaded, 5 letters
They're sometimes loaded on the field, 5 letters
They're sometimes stolen, 5 letters
Thule, Pearl Harbor, etc., 5 letters
What an agent has covered, 5 letters
What Meat Loaf went around in Paradise by the Dashboard Light, 5 letters
You must be quick to steal them, 5 letters
You need speed to steal them, 5 letters
It's usually set at lower amounts in the first years of a player's contract, 10 letters
What bonuses add to, 10 letters
You get this before a bonus, 10 letters
Part 4 of dream situation, 9 letters
Number system used by the Babylonians, 9 letters
Bottom-of-the-barrel, 6 letters
Furthest from noble, 6 letters
Like the lowest common denominator, 6 letters
Maximally meanspirited, 6 letters
Meanspirited to the max, 6 letters
Superlatively inferior, 6 letters
Lou Brock or Tim Raines e.g., 11 letters
Kenny Lofton's specialty, 12 letters
...changing the routine at a military installation?, 18 letters