Good online players know instinctively when they should play their cards or not. However, the strongest players in the game also keep tabs of every opponent's stack size, in particular those opponents who have yet to act in a hand and are short stacked. Maintaining a tally of short stacks at the table, will have a big impact on your call to raise, call or fold.
That could be severe but it is fully accurate where as an example you have gotten a nice looking hand like QJ suited in late position, that you would normally raise first in. However, if one of the blinds is a short stack and is itching to move all in, you'll probably want to reconsider this showdown primarily based on both your stack sizes. Although your adversary could be short stacked, him winning a questionable outside bet hand could make you a short stack.
Some players simply go to far out of the way to attempt to decimate a short stack, without thoughtfulness of their own situation if they are way behind, and lose. Too frequently, too much is hanging in the balance where you are only a narrow favorite to win the hand, because some players may feel invincible against a smaller stack.
The challenge in pressuring short stacks to play with you is that since they do not have much of a choice, you will quite often participate in a negative EV situation. Now this is not true if you have gotten a great stack or a green mzoned where you can easily yield losing it. The theory behind this is that if you enter in enough of these hands you're going to be positive EV and can seriously improve your prospects of coining it big in the tournament.
It is a calculated strategy and will also fare well when you're three or four handed, and the blinds are rather gigantic to all the players left at the table. In that sense, aggression does pay in the long term and most pro advice that you read about in these spots will agree. However, at a full table - you want to take correct note of stack eventualities of everyone remaining.