I'm torn here, Ambers has a tremendous resume, one that is not mentioned enough, though he was beatable by true highest level type guys, Castillo may not be quite there for ability. Castillo is no doubt the stronger man here, could he impose his will? I'm picking the greater lightweight to grind out a decision. Ambers.
Castillo does what Armstrong did to Ambers pretty much, he has put the heat on better boxers like FMJ, Johnston and Casamayor. JLCs bodypunching, presure and strength would be the difference
Ambers is a very underrated fighter in my opinion. He'd control the action from the outside and keep things even on the inside. I'll say Ambers by 9-6 decision.
ambers was probably underated but that is not a surprise when you consider just three of the other lightweights that were around armstrong,mclarnin and canzoneri ,ambers and catillo would be a great fight both were aggressive i would favour ambers to pull away over the last few rounds to gain a ud.
Ambers was simply much more proven than Castillo was, and Castillo never really impressed me with any of his traits, though he was a very good fighter. I doubt he'd have been able to beat the guys Ambers did.
Ambers out boxes him here on the outside. Eventually Castillo will get inside but Ambers matches him in there to pull out a reasonably exciting but definitly clear UD
Castillo's hard punching, keep Ambers on a tight leash here. They trade wild combinations with Castillo maintaining a slight lead. As they go into the late rounds Ambers starts to connect & Castillo is feeling it. A late flurry wobbles Castillo and Lou finishes it in the Thirteenth with a hard combination.