A quick explanation of how Jury selection works:
As soon as someone hits alert on a post, the DU software forms a Jury to adjudicate the alert. It does this by selecting the first eligible person who clicks on one of DU's busiest pages (Latest, Greatest, Latest Videos, a top-level forum page, etc.). "Eligible" means that the person is signed into DU, and has "Available to serve on DU Juries" set to "Yes" on their Account Settings.
The software then "rolls a dice" by picking a random number between 1 and 100, and compares that to the person's chance of serving on a Jury. If the chance to serve is 80%, and the software rolls 1-80, then the Juror will be seated, but if it rolls 81-100 they will not be seated. The lower your chance to serve, the less likely it is that you'll be seated when the software performs this check. (If your chance to serve is 100%, then you will be automatically seated every time.)
The penalty for a removed post includes a 20% reduction in your chance to serve, so with a single post removal, your chance to serve is 80%. This means that if the software selects you to serve on a Jury and then "rolls the dice" to see if you will be seated, you still have a 4 in 5 chance of being seated, which are good odds.
After 90 days, assuming you have no further posts removed, the removed post "falls off" and your chance to serve will go back up to 100%.
I hope that makes sense.