You notice where the cue ball ended up after he shot the combination. It was actually a fairly big ball to shoot at because of its proximity to the rail. Dennis knew all that and knew he could play safe on the ball close to Scott's pocket. That gave him freedom to fire away.
Great One Pocket is all about continuing to make balls, no matter how you end up. Ronnie Allen was the greatest for his ability to improvise and continue run outs when it looked like he had no shot. He would create a shot, be it a three ball off angle combo or some ludicrous kick into the pack. Balls just kept falling in when Ronnie was at the table. It may have looked lucky but after you watched him do it all day you began to realize there was a method to his madness. To bad there isn't more tape of Ronnie in his prime.
What made Efren the best of his era was also his ability to continue to make shots even after it looked hopeless. If he could see it or even envision it, he could make it. And usually did! Not to mention Efren's uncanny cue ball control, seemingly able to thread the needle to get perfect position with zero margin for error. He took many near impossible shots with the game on the line and delivered time after time.