Ok, since you all are so interested in probability... I will give you a nibble.
Right now I estimate we have around a 75% probability of closing this week below 1899, but we also have around a 60% probability of touching prices above 1899.
Not Shown: Also, we have a 50% probability of touching 1858 next week. Probability of touching 1878 was a minimum of 75% this week... Probability of touching 0.5ATR above this weekly mean has kinda maintained at 70%+ since early 2013. LoL...
70% probability doesn't sound like much unless you know how to do compound statistics. A 70% OR probability compounds to a 97.3% probability over three bars. So, this market has been maintaining a 97.3% probability of touching prices 0.5ATR over what is essentially a 6SMA over each three weeks.
Ok, so... Let me just state some facts simpler. This market has been maintaining a 90%+ probability of deep sixing any shorts done 0.5ATR below average... Within three weeks... By 1ATR+. Probability of price staying below -.5ATR week to week has maintained around 10%.
So, if we are -0.5 ATR below average, we have a 90%+ probability of going 0.5 ATR higher than average. Over two weeks, that compounds to a 99% probability.
The OP's question is very valid. Yes, there are ways to judge the probability of a bottom with some accuracy. But, market behaviors do eventually change. Markets pre-2013 were heavily cyclic. This market is currently behaving normally. Just like the 2007 bull market, or the .com bubble runup.
There are more factors at play if you want to get close to calculating current true probability... Number of bars up/down, wave counts, momentum, and momentum divergence. My probability estimates are 90% mechanical, and 10% subjective. I do watch news closely as certain events like fed policy changes can cause probability to be shifted a bit different than what the numbers say.
Note: This chart is a bit stripped down... My normal chart setups and code I keep secret nowadays.
xelite777, you can PM me if you want a glance. Will probably put you into a state of belief shock... Jk, lol!