Moving up more than 1 class in claimers would be skipping the usual "Up to the next claim price' like 10K to 12K and going to a double up in base claiming price like 10k to 15k.
Sometimes it's also possible to drop in a claiming race at a higher price if it means you'll accept outside post draws. That also could be considered a class up in claimers....inside to outside post
For Condition races, I see no reason to do a double up in class and go to a tougher a race than necessary, since there's no possibility you'll lose ownership.
The question about :
"...what fractions would people suggest to be fast?"
that depends on class and gait too much to give any specific number.
One number that can be used to toss a ppline is the breaking-point quarter (or BPQ) referred to in this excellent thread.
http://www.paceadvantage.com/forum/s...ad.php?t=64718
reply 19
