How can I get my boys to stop this bad habit???

[Beercules]

Get the belt out bro

[Redd Foxx]

Because now that you say it, when they slip they are putting a lot of weight on their back leg so it makes it hard to pivot and/or roll out...

Yea, that's what happens. It was a little easier for me to overcome because I've had it ingrained in my head from music, jiujitsu, and other training that stiffness is counter-productive.
In boxing, I think most bad behaviors occur for lack of options or confidence in those options. Maybe drill the dip to the left/left hook (see below). This gives them a deliberate option and strategy. The first time I got this to land in sparring it gave me a huge confidence boost and I never had a problem slipping to the left again. Whatever it takes to make them confident in their options and subsequently loosen up.


Mike Tyson gives some of the best examples of slipping to the left and working hooks and uppercuts off it but I can't find any gifs to illustrate. Definitely have them watch some early Tyson though. Crazy slipping to the left. Several throughout this one but specifically check out 2:57.

[Rockin']

Where are you boys' eyes when they are sparring? Where are they looking on the opponent?

[Rockin']

You could hook their ******* up to a car battery and each time they slip that right hand to the right you just give 'em some juice. A day or two of that and the slipping problem should be cured.

[Dip_Slide]

It's actually normal to defend against the jab by parrying it with the rear right glove and dipping slightly to the right, this is good for countering with the right hand over the opponent's extended jab, slipping the jab to the inside (left) opens up the left hook to the body or the left hook uppercut upstairs.

Dipping to the right can also be an effective defensive technique when combined with bending at the waist and moving either toward ur opponent to grab them or to move ur head away like James Toney or Floyd Mayweather.

Slipping to the outside is not wrong but doing the same thing over and over again against experienced opponent is bad and dangerous cuz u can be timed, variation between different defensive moves is key.

[JadeaKallen]

Blocking is easier to teach and quicker to learn than avoidance movements. You could teach your boys to block to compensate for their lack of movement.