this question has been asked many times mate.
success is never guaranteed just because a player has decent ability or decent rating either. even if a player has good ability, good rating and good attributes... nothing is certain. you'll have to try the player in your own team and see for yourself.
however, it is common sense that a player with decent rating (current, let's say over 65% for lower competitions and over 70-75% for top class ones) and good attributes at consistency (to have consistent match ratings), important matches (usually combined with pressure), injury proneness (how often he's likely to get injured), pressure (if team is playing above expectations or he's wanted by bigger teams) and adaptability (if he's likely to feel country sick)... and depending on his position (target or fast) his height, strength, stamina, balance, positioning, pace, off the ball and dribbling... well, it's a win-win anyway.
success is never guaranteed just because a player has decent ability or decent rating either. even if a player has good ability, good rating and good attributes... nothing is certain. you'll have to try the player in your own team and see for yourself.
however, it is common sense that a player with decent rating (current, let's say over 65% for lower competitions and over 70-75% for top class ones) and good attributes at consistency (to have consistent match ratings), important matches (usually combined with pressure), injury proneness (how often he's likely to get injured), pressure (if team is playing above expectations or he's wanted by bigger teams) and adaptability (if he's likely to feel country sick)... and depending on his position (target or fast) his height, strength, stamina, balance, positioning, pace, off the ball and dribbling... well, it's a win-win anyway.
