▁facil itate ▁rock abil ly ▁or ▁bl u egr ass ▁" s lap " ▁playing , ▁while ▁the ▁thumb ▁of ▁the ▁right ▁hand ▁rest s ▁against ▁the ▁side ▁of ▁the ▁finger board . ▁The ▁strings ▁are ▁usually ▁pl uck ed ▁over ▁the ▁finger board ▁near ▁the ▁end . ▁The ▁left ▁hand ▁is ▁used ▁to ▁stop ▁the ▁strings ▁by ▁pressing ▁down ▁with ▁the ▁f les hy ▁part ▁of ▁the ▁finger , ▁generally ▁using ▁the ▁ball ▁of ▁the ▁thumb ▁at ▁the ▁back ▁of ▁the ▁neck ▁to ▁obtain ▁pressure . ▁ ▁In ▁the ▁highest ▁positions ▁on ▁the ▁finger board , ▁where ▁the ▁neck ▁on ▁an ▁E UB ▁gets ▁consider ably ▁th icker , ▁the ▁left ▁hand ▁usage ▁can ▁be ▁modified ▁with ▁the ▁whole ▁hand ▁being ▁brought ▁round ▁to ▁the ▁front ▁of ▁the ▁instrument ▁and ▁the ▁thumb ▁taking ▁the ▁place ▁of ▁the ▁index ▁finger . ▁These ▁positions ▁are ▁called ▁the ▁' th umb ▁positions ' ▁in ▁double ▁bass ▁parl ance . ▁In ▁these ▁positions , ▁it ▁is ▁necessary ▁to ▁rest ▁the ▁neck ▁of ▁the ▁bass ▁against ▁the ▁player ' s ▁left ▁shoulder ▁in ▁order ▁to ▁support ▁the ▁neck ▁against ▁the ▁pressure ▁of ▁fingers ▁on ▁the ▁strings . ▁On ▁the ▁shorter ▁scale ▁E UB s , ▁bass ▁guitar ▁f ing ering ▁can ▁be ▁used ▁over ▁a ▁large ▁portion ▁of ▁the ▁finger board ▁and ▁thumb ▁positions ▁may ▁not ▁be ▁necessary . ▁On ▁the ▁longer ▁scale ▁models , ▁due ▁to ▁the ▁larger ▁distances ▁between ▁notes , ▁the ▁double ▁bass ▁( Sim and l ) ▁f ing ering ▁method ▁usually ▁has