As long as I have played this game, I am still very uncertain of the effects of fatigue on both position players and pitchers. I am in one homerun oriented league right now, and most teams are letting their players get fatigued, some down as low as 80%, but most somewhere between 90%-95%. All these players seem to be playing to their maxium and still hitting just as many long balls. How does fatigue effect these players?

I bet their fielding is atrocious.

Fatigue is insidious, because you won't see performances fall off a cliff unless fatigue drops below around 80%, but they will be affected.  I was in a TOC Final where I was playing a pretty evenly matched team, and I'm convinced the other team won Game 7 because his players were rested and playing at 100% and mine were not and playing at 90-95%.  He punted Game 1 with scrubs to make sure his players were at 100% for the rest of our matchup.  I generally play position players and pitchers at 90% or higher, but that's probably too low -- a lot of veterans here use 98% as the cutoff.  For position players, fatigue seems to affect defense before it affects hitting. 

playing a guy at 90% is like trading your .300 hitter for a .285 hitter. because of statistical variance you often wont notice any difference in the short term, but in reality your odds are better if you rest him every 10th game and play your .200 hitting scrub instead. That's just hitting, you're taking a downgrade in the field too. makes no sense to play tired players earlier in the season because there's more remaining games to suffer the consequences.

Posted by rbow923 on 6/25/2010 2:06:00 AM (view original):
playing a guy at 90% is like trading your .300 hitter for a .285 hitter. because of statistical variance you often wont notice any difference in the short term, but in reality your odds are better if you rest him every 10th game and play your .200 hitting scrub instead. That's just hitting, you're taking a downgrade in the field too. makes no sense to play tired players earlier in the season because there's more remaining games to suffer the consequences.

Do you have data to back this up or are you speculating.  Prior to his inauspicious departure and demise, Ozomatli had been talking to me about some tests he was doing with fatigue and this is not what he explained to me that he found.  Fatigue obviously  has an effect on Pitchers but the proof on hitters is less obvious.  I would be interested in any data that you have to back up your statement.

Ok so the question is what number should you rest starters / pitchers? I have mine set on 75. I assume that is way to low?

Depends on the situation.  For a must-win game, I'll take Ted Williams at 85% over Gerald Williams at 100. 

If it's early in the season, and especially if I'm playing a team from the other league (or a team I don't expect to be fighting for a playoff spot), I'll rest my stars if they're anywhere near tired.  And rest them all at the same time, too, and start a crap pitcher.  I try to use my best players at the same time, and against the "right" opponents. 

I look at it this way.  If I've got a 90-win team, I'm going to try to have as many of those 90 wins as possible be against division/wild card rivals. 

I noticed this in a league where I had Coors as my home park.  It's actually a progressive and the last two seasons, I've been well ahead in my division and then collapsed hard at the end. I suspect the reason is that most of my hitters, because of the extra ABs, were between 85-90%. They were still mashing, but their errors went up a bit and my pitchers were suddenly giving up more hits...which I suspect is a symptom of decreasing range in the field.

Others have also said fatigue hits hardest on defense, which makes sense if you think about it.  In RL, a tired power hitter could still step up to the plate and bomb one, but his feet and hands would be a lot heavier in the field.  You'd expect his range and reaction time to be slower, and maybe his focus a bit off as well.  Those factors could have an effect on hitting as well, but it doesn't take as much energy to swing a bat as it does to field a position.

I have always thought that the fatigue setting was for the purpose to stop the player you are using from exceeding his real life AB's or IP's. Otherwise you would be starting Gagne as a SP, but you don't because he would exceed his real life IP quickly. I would like to see the sim, punish more players exceeding their real life AB's and IP's, I think that would make it more real, and force people to manage their teams correctly.

Posted by Bluecrew2 on 6/26/2010 12:24:00 AM (view original):
I have always thought that the fatigue setting was for the purpose to stop the player you are using from exceeding his real life AB's or IP's. Otherwise you would be starting Gagne as a SP, but you don't because he would exceed his real life IP quickly. I would like to see the sim, punish more players exceeding their real life AB's and IP's, I think that would make it more real, and force people to manage their teams correctly.

Yes, starting the RP years of Gagne could chew up his innings quicker, but not neccessarily because most RP years including Gagne's have an IP/G of less than 1 up to 2. The minimum PC for a SP is 40 and Gagne would get killed at 40 let alone say 100. So, the in-game fatigue negates any chance of getting anything close to a QS anyway.

Posted by rbow923 on 6/25/2010 2:06:00 AM (view original):
playing a guy at 90% is like trading your .300 hitter for a .285 hitter. because of statistical variance you often wont notice any difference in the short term, but in reality your odds are better if you rest him every 10th game and play your .200 hitting scrub instead. That's just hitting, you're taking a downgrade in the field too. makes no sense to play tired players earlier in the season because there's more remaining games to suffer the consequences.

I agree. But to expand a bit fatigue does not mean the same thing as effectivness. As far as hitting goes, I estimate efectiveness drops 1% for every 2 points of fatigue until 90-95%. Then it drops 1 to 1 until you hit 80% or so; afters which effectivenes drops off a cliff.

Me personally, I hardly ever allow ANY of my starting position players to play at less than 100%.  In fact, when I hover over the mouse in their fatigue column, and when their fatigue level gets to 5% overuse, I rest them for a game.  This way, they're 100% for the entire season, assuming they had the appropriate number of RL PAs for the position in the lineup in which they're hitting.