Does anyone use a particular rule of thumb when to waive a high priced ($6-$7 Mil) everyday player who is severely under-performing? Such as 10%, 20%, 30% etc. of the season, rather than suffer the consequences of a possible full season of pitiful performance.

Almost never.  Only if I can figure out a good reason why they aren't performing as well as I had expected.

Yup.  I almost never waive a player for underperformance.  I use the WW either to dump my 200K guys, or if suddenly find I have a hole to fill (like I didn't draft enough IP or PA).

I have a Jackie Robinson who is batting .249 when is actual average is over .340 I believe. I am almost at the all-star break.  I'm sticking with Jackie though even if this is his worst performance history on planet earth.  Its a good feeling.

I concur..stick with him.  I recently had a season of Bobby Veach (actual stats .321 .388 .406) hitting .188 .240 .252 at the all-star break.  I stuck with him, hoping he would regress back toward his stats.  He hit over .500 for the rest of the season and finished at .303 .374 .376 and I used his tear to finish first in the division.

The reverse is true -- players that start off the season outperforming their real life statistics almost always underperform over the latter part of the season.  I had a Ted Williams in a theme league who was hitting just under .500 at the All-Star break and ended up under .350.  (If my arithmetic is correct, that means he hit under .200 over the second half of the season.)

The "odds" that your grossly underperforming player will improve over the course of the season are better than the "odds" that the player from the waiver wire who you use to replace him will be an extreme overperformer.

The rule of thumb I use is when I get ****** off enough at the player, I let my left brain overrule my right brain and out they go.

I recommend waiving your players as often as possible.

I have had some success with it. In a league i drafted two so so SP's and dropped them with about 20 games to go in the season and picked up a big time pedro martinez and a cookie off the bench as a PH. it worked perfectly. Pedro brought me to the ship, i lost, but won the TOC and pedro only gave up one run in the seaosn and playoffs with pedro and he was just as good in the TOC.

Robinson 0-4 again,maybe it is worrth dropping him. Be patient Matt, be patient.

Well truemen got it. After another 0-4 game out he went. I admit it, I folded under the pressure...........aggravating bast**d.....

agreed

Robinson 0-4 again, average still at .252.  If he continues at this pace, his average will be still be 90 points lower than his worst performance history stat. C'mon Jackie give me some love!

Just think, you can have the dubious "worst performance" honor.

Well it is something to shoot for anyway

actually when that happens I'm never ashamed, I kind of like my spot in history. Its not like I am not trying!