If you hover the mouse over the variables in the Test Conditions section of the Event dialog (or you can right-click and select Show Tooltip) you'll get a description of the variable.
position is sort of the inverse of rank. The first person to bust-out of a tournament is position 1. The 2nd to bust out is position 2. So it's the order of bust-out.
Your schedule may have rounds and breaks. As an example:
round 1
round 2
round 3
break (1)
round 4
round 5
round 6
break (2)
round 7
round 8
...
Each of these is a level. Levels are either of type Round or Break. So, round 1 is level 1, round 2 is level 2, round 3 is level 3, break 1 is level 4, round 4 is level 5, etc.
The variable 'roundNum' represents the current round number, and the variable 'breakNum' represents the current break number. During a round, the 'breakNum' variable will be the number of the LAST (previous) break in the schedule. So, if it's currently round 8, 'breakNum' will be 2. Likewise, during breaks 'roundNum' will be the number of the last round. If it is currently break 2, 'roundNum' will be 6.
There was in error in my previous message. I think I've made a confusing inconsistency when putting the event conditions together, because the "inTheMoney" variable represents the rank needed to be in the money. In the Points for Playing formula, there is an "inTheMoney" variable and an "inTheMoneyRank" variable. The first is 1 (true) if the player is in the money, 0 (false) otherwise. The second represents the rank needed to be in the money. Unfortunately I did not make these consistent in the Event Conditions.
So, for the event "Player to bust out not in the money : !inTheMoney", the formula should actually be "rank > inTheMoney".
That being said ... the first two events in my list ('first player to bust out' and 'players to bust out on the bubble') will not both trigger at the same time (unless you have a tournament where only the last place player doesn't win a ranked prize). The position variable makes the first one very specific, and only fires for the first player to bust out. Likewise with the second one, the inTheMoney variable makes it very specific.
On a similar note, the event 'Player to bust out not in the money' WILL trigger at the same time as the first two, since it will trigger on any player busting out who does not make the money. Therefore, it is lower in the list so that the first two, more specific events, will trigger appropriately, and the third, less specific event will trigger on other bust-outs.
I hope I haven't confused things even more...