With Venus, her whole game is nothing like it used to be. I'll break it down stroke for stroke here:
Serve: Not as powerful or as well located as it used to be. With the front foot parallel to the baseline, she isn't allowed to serve as hard as she used to and her serve up-the-middle on the deuce and out-wide on the ad are a mess. They both stay in the strike zone of her opponents and aren't flat enough for aces. Most if not all of Venus' serves has slice on them now. She can use it now and then, but not on every serve. Someone needs to tell Venus that she needs to have her front foot pointed in the direction of the net post (like she did from the beginning of her career until 2004-2005ish) to her right and jump into the court to get the same first serve she once had. Her second serve is more solid now, but a good kick serve like Serena's would help her cause.
Forehand: Don't try to hit a forehand like Venus at home folks. You should never have your right foot in front of the left foot. Plus Venus has a hitch in her swing with a double take back. She isn't getting enough topspin and racquet head speed from her swing through the forehand. It is too flat and the stroke is too rigid now. Venus needs to start swing up the back of the ball more to get that heavy ball she used to hit enough in 2004. She needs to smoothen out the stroke.
Backhand: This is prob her most regressed shot. Doesn't hit enough winners on this side anymore, is ALL open-stance (too much and too open for me), no disguise on it anymore and the backhand down-the-line isn't what is was. She is making a ton of errors off this side and it is killing her in tight matches. Again, this shot is too rigid in the technique and isn't as smooth as it once was. Venus used to hit a heavy ball off her backhand and would close her stance to attack balls (much easier to attack a ball with a closed-stance on the two hander than completely open because you have no body weight going into the shot (which is why Venus has to run through her backhands to get weight behind them now) and there is more body control when the stance is closed). Venus needs a lot of work on this side because it let her down in Oz and at the USO qtrs along with her serve.
Volleys: Only complaint: forehand swing volley of 2000-2001 is missing.
Movement: Not as quick as she used to be. Wimbledon was the only time last year where she moved really well on the court. Other than that, her movement was average from the standards she use to have in 2000-2003.