public static Deck selectOne(Deck[] old, float[] perf, float total){
	
	float target = ((float) Math.random())*total;
	float running = 0;
	for(int j=0; j<perf.length; j++){
	    running += perf[j];
	    if((running > target) || (j == perf.length)){
		return new Deck(old[j]);
	    }
	}
	return new Deck(old[old.length]);
    }