I'm guessing that if you are a natural DLer, then after you hit certain level of strength, you're going to need to do some (maybe not much, mind you) dedicated DL training to up your numbers.
Performing Deadlifts To Increase Strength
Let's re-address the issue of performing Deadlifts to increase Deadlift Strength.
The issue with this approach is that Technique is altered with this approach.
It ensures Poor Technique is developed and maintain.
Auxiliary Strength Training Exercises
The optimal method of increasing strength in the Deadlift, any movement, is to employ Auxilary Exercise that are smilar in nature to the movement.
Auxilary Exercise are essentially disposable; realiasticly rotatable exercise.
Auxiliary Exercise are rotated in and out of program over time.
Exercise Variety
Research on this has been posted multiple times on this site.
Varying Auxiliary Exercises have been shown to increase strength for athletes and increase size in Bodybuilder to a greater degree than constantly performing the same movement.
Auxiliary Exercises allow a lifter to minimize or to some degree override the sticking point in a movement.
An Example
One of the most effective metod for Conventional Deadlifter is...
Dr. Bret Contreras
Earlier this year I got a paper published in the SCJ titled, Are All Hip Extension Exercises Created Equal (click to download). I’m very proud of this paper and feel that it’s...
bretcontreras.com
This applies more so to Conventional Deadlifter than Sumo Dealifters.
1
) 90 Degree Back/Hip Extension
The overload occurs at the Top Part of this exercise
This exercise will increase Top End Lockout Strength for Lifter who struggle in this part of the Conventionl Deadlift.
2) 45 Degree Back/Hip Extension
The overload occurs in the Middle Range of this exericse.
Buiding Strength in the Middle Range will help those who stall in the knee area of the Conventional Deadlift.
Hang Power Cleans
As with 45 Degree Back/Hip Extensions, what I found was the my sticking point shifted from just below my knees to just above my knees.
3) Good Morning
The Good Morning amounts to being a Standing Back/Hip Extension.
The overload occurs in the Bottom Range of this exercise.