Christopher in Ontario, Canada emailed me to ask about [tag]indoor softball drills[/tag]. I copied and pasted this response from Jim. 
Sometimes to break up the [tag]softball[/tag] [tag]drills[/tag] we change it up and have a relay.
Five Ball Relay Race
Players form 3 – 4 lines of 3 or 4 players (try to mix speeds here to keep it competitive)
You will need 3—4 buckets for the 5 balls for each team. You will need one bat for each of the 4 teams.
X……………50 yards……………………..( Ball Bucket )……………50 yards……………………( Bat )
Place 5 balls in the ball bucket.
The first contestant starts at the X and runs the 50 yards to the Bucket and picks up a ball then runs back to the starting line drops the ball and goes back and gets the next ball. Repeat till all balls are at the starting line.
Next the player runs past the the empty bucket to the bat and swings the bat hard (5) times. Then returns to the starting line picks up a ball and returns it to the bucket. Repeat until all the balls are back and then contestant number 2 on your team goes.
Summary
Players all start at point X
Run to the ball bucket pick up a ball and run back to point X. Drop the ball at point X and run to the ball bucket and get another ball till all the balls are at point x. After all 5 ball are picked up and dropped at point x the player runs past the bucket to the bat and takes 5 swings.
Player then runs back to the balls and starts putting them back in the bucket 1 at a time. When all 5 balls are back in the bucket and the player gets back to point x player 2 goes.
Great team builder and endurance.