With premeasuring in for this edition, I finally sat down with Excel and made up a few charts for deep strike guidance to determine exactly how risky any Deep Strike might be. Remember, you need to include the width of the circles around the center you need to make after the initial model is placed and the 1" distance from the enemy. A 3-d plot of this that accounts for the possible directional scatter of the dice is forthcoming once I get MatLab working for this data set.
These ranges work for a scatter dice with 1/3 hits and have remained unchanged over the past several editions. More interesting is the contrast for charge ranges - the ranges for a standard charging unit have the same plot as the scatter distance from 2 to 12 (just normalize the probabilities!)
More interesting to me is the influence of Fleet on the charge range of some of my favorite Daemon units (Fiends and Seekers). This calculation is conservative and based on enumerating the entire range of possible outputs assuming you always reroll the lowest dice result.
In actuality you might occasionally want to reroll both dice results (for charging 8" when one dice is a 1 for example). I will incorporate the fully accurate ranges when I finish up with the MatLab plots (Excel is really pretty poor for these kinds of calculations). I also plotted the old charge ranges with this plot for a unit with Fleet.
These are the probabilities when only rerolling a single dice to succeed a charge at 2", 3", 4" through 12". The charge range for 5th edition is the standard 6" charge plus a fleet move. For beasts/cavalry this remains accurate due to the change to a 12" move for those units.
The relative closeness of these curves demonstrates that the nerf to charge ranges is most pronounced in the 7" charge range (which is where you used to have a guaranteed assault). Remember, these numbers are a bit conservative as well.