Funny to read a few of the MANNNNNNNYYYYYYY posts responding to the blue one. Most people don't seem to understand statistics.
Short lesson.
Confidence level is the probability of having the desired result as related to the standard deviation.
If you kill the baron 100 times under the new drop rate you would have a 68.27% confidence level of seeing it at least once.
If you kill the baron 200 times you would increase the confidence level of seeing the mount drop at least once to 95.45%
Under the old drop rate of 1/5000, killing him 5,000 times you would only be at the 68.26% confidence level.
Personally I've killed him several hundred times, 74 to get tiddly's dungeon tier 0.5
Magister's Leggings, and never seen the mount drop; however, most of those events were under the old drop rate.
And that illustrates the confidence level right there the pants have a 9% drop rate or 1/11.1. I had to take that out nearly 7 standard deviations to see them drop once. Funny 3 runs later they dropped again.
& now we all know a little more about math