ID	SOURCE	SCORE1	SCORE2	SCORE3	.....	SCOREN
66521	SRC1		12		34		27			67
88921	SRC2		34		56		59			88
66524	SRC1		56		66	
3341	SRC1		44		59		67

##</code><code>##

print join " ",  reverse split foreach  
	map  { $_->[0] } 
	sort { $a->[1]<=>$b->[1] || $a->[0] <=> $b->[0] } 
	map  { [ $_ , (split)[-1] ] } 
	grep { /SRC1/ } <> ;