Originally Posted by LuckyR
to figure out what to change to, you need to have a firm grasp on why you are losing points (a la Winning Ugly) and use that to adapt.
^ 100% This.
OP, you have to really see what your opponents are doing to beat you. You can't be vague and just say they "played slightly better". Get specific.
LuckyR gives the example of playing two-back as an adjustment. This is usually done if one or both of you are weak returners and/or the opponent's server is strong. It gives both players more time and space to respond when your opponents are getting ready to smack your weak returns.
Another problem I see a lot is players not "holding the line". When your opponent is at the baseline getting ready to hit the ball, the player on the same side should always guard the down-the-line/alley shot. Lots of times, players will break to the middle too early which allows the opponent to hit an easy winner down-the-line.
So do like LuckyR says and really take inventory of the exact types of shots that are beating you. You can't make an adjustment unless you have this info.