right, just done a quick Google, and found a few websites like this one:
http://www.drmalpani.com/book/chapter1a.html written for TTCers who say that:
Also found this study, which seems to suggest that TOTAL numbers of count (and semen quantity/sperm count) are increased with each additional day of abstinence:
http://www.reproduction-online.org/c....full.pdf+html - it's worth looking at the diagram in the "Restults" section. So according to that one it might be best to DTD less frequently even for blue.
You'd have to figure out the total no. of sperm based on number of attempts within the fertile window to know how many attempts to have...