Common Fangtooth

Don't forget to reference these helpful links as needed: The Basics, Glossary, How To Read a Workout, Pacing Table. 

Warm Up
300 swim
8 x 50 @ b+20
Fly/Back, Back/Breast, Breast/Free, Free/Fly
2 x 100 kick @ 15 seconds rest
4 x 75 swim @ b
(1200)

Main Set
4 x 100 @ b +10
2 x 50 easy @ b +20
3 x 100 @ b +10
2 x 50 easy @ b+20
2 x 100 @ b +10
2 x 50 easy @ b+20
1 x 100 @ b +10
2 x 50 easy @ b+20
(1400)

All 100s are to be swam descending, knocking off the slowest 100 as you move down the set. Example: If my normal 100 base is 2:00, I would do the first 4 x 100 holding the following times: 1:50
1:45
1:40
1:35
That last 100 should be a FAST time for you. For the next 3 x 100, I would drop the slowest time from the previous set. So on the 3 x 100s I would try to hold:
1:45
1:40
1:35
The 2 x 100 would be holding 1:40 and 1:35, and the last 1 x 100 would just be trying to make 1:35.

You should be getting a decent amount of rest on the 100s, and the 50s are meant to be recovery.  This is a good set for working on pacing yourself in the early 100s and finishing off with some speed.

Warm Down
8 x 25 @ :30 breathing 3/3/5/5/7/7/9/9 by 25
4 x 25 0 or 1 breath @ :45
(300)

Total: 3100