The act of running bases, or a player's skill in doing so(noun)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "baserunning" in a sentence
"Their baserunning is bad, and their overall fundamental play is worse."
"Hilton Head American will practice twice between now and Tuesday, though Coach Mlodzinksi said the workouts would be more for ironing out a few kinks -- such as baserunning -- rather than all-out drills to correct major shortcomings."
"He has great speed but is prone to baserunning mistakes."