A great way for BJJ players to improve their groundwork is to practise techniques from a throwing position and then transition into ground work from there.
A lot is written about the benefits of training in Judo for BJJ practitioners for their ground game and it goes beyond time standing on the mat. The actual fast paced rules of Judo can help BJJ practitioners to become submission hunters and improve their oseikomi (pinning) like Judoka on the ground rather than playing for points.
It is the BJJ practitioner that cross trains regularly in Judo that will reap the benefits and improve their skills. Once a BJJ match hits the floor, it stays there but imagine the BJJ practitioner who could finish matches within minutes due to being perhaps just 10% better at throws, submission hunting and transitions.
BJJ practitioners can benefit so much from training in Judo for a lot of reasons…
A great example is Xande Ribeiro cross training in Judo with top Judokas in the USA:
BJJ black belt Joe Rogan recently talked about just how dominant a grappling art is Judo and how BJJ players really need to include it in their training regimen: