FH with consistent wrist extension from backswing to contact? Lag to me either means 1) angle set followed by angle release ... or 2) lag in time ... like @Curiosity used in shoulder locking discussion. But with a fixed wrist extension, the racquet is merely pointing back because the arm rolled. 
We would have ruined the FH with terminology here with or without coach or YT help.
Speaking of terminology ... isn't "racquet lag" a bogus term for a ATP
On some Fed FHs ... he releases some forearm/racquet angle so those are "rolled and lagged" and others just "rolled".
Do you think this post should also be cursed? Do you think Mad dog already is ... and flipping off this post? Probably not ... too long.
IMO
This:
is infinitely more difficult to time than this:
The late big arm rolling and unrolling is always going to be harder to time than a longer swing. Also ... if you measured the full swing path by the racquet tip instead of the hand ... not sure the ATP is even shorter.
I know I promised no more golf analogy ... but it would be like saying the following is easier to time for the rec golfer:
I know brother @J011yroger says it's the cr@p legacy FHs that make it hard to learn the ATP FH ... and it would be easy/easier to learn from scratch. Probably ... never doubt the Jolly... but I would say the important bit would be the repeatable rec FH they brought to matches. For example ... go show any of my past 4.5 tournament opponents, or USTA team members, or Wed night doubles league players that they would have been better rec players if they had learned to do Djokovic pic #2 above ... and you better not be telling them that during indoor court time. You would be run off with offensive ridicule and laughter. Even better ... go try and sell Djoker pic #2 to any of my past wife's 3.5 USTA team mates ... who 90% had never made a ball spin on purpose in their tennis career.
OK ... I kid a little ... if I was starting over as a 4.5 25 year old tournament singles player (baseliner) ... I would go for the ATP. Also ... even without the big arm rolling/lag ... I think many would benefit from a healthy sized backswing, but keep it on the hitting side of the body. To me ... that is good middle ground ... shortened the swing, but still providing the repeatable rec FH with a decent size backswing. JMO.
One other thing on the "shorter reaction time. I'm glad @SystemicAnomaly is in the house ... because we have talked about how we process an incoming ball, and when our "moment of commitment/swing" is.
To my surprise, I found out my moment of "swing/go" calculation is at the top of the backswing ... not dropping/looping, and not at the slot (Djokcer pic #2). Maybe the pros are good enough for later "go" ... certainly looks like Fed adjusts "go" on the drop on some shots. But for me ... no chance I could even delay my "go/swing" committed point to the drop. I've hit a lot of tennis balls ... so I'm going to guess most here would find out something similar if they go check where they commit on the tennis court. And by commit ... I mean the calculations were done ... you are swinging to hit the ball ... unlikely to have much deviation from the calculated flight path. Si if that's typical for a rec player ... it's a false analogy to look at that slot position, and say that is where your swing started from, so you have a shorter swing than say a WTA swing. The start of your rec swing probably started before Djoker pic #1 above. If you are able to delay it to the PTD drop ... than good for you, and you have a real case of "shortened swing/reaction" time ... but still stuck with the late big arm rolling.
The WTA will probably convert to more ATP FHs when they get one of these:
J
Is there an echo in here? (See posts #39 & #37). Great minds and all that!
Thats what i wanted to say
. I am an advocate of a short compact simple backswing. make it easy to replicate and reproduce. i am not a fan of complicated pomo pat the dog stuff, formula for mishit and loss of power.
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it just reminded me of a joke >40 yrs ago...........................
back in 1970s most of rural poor areas in some countries, the undies're very very rare n only the educated city ppl'r wearing undies. an 18 yo village girl who wanted to catch the trend n attract attentions of boys bought a pair of pink floral undies n she wanted every1 in her home town know dat she's wearing fancy city ppl's undies, so she asked a neighbor who could read/write made a banner saying 'pink floral undies inside' n put it on her pants. off she went out to the main street in her home town to show off her new undies................all of a sudden the gusty wind blew off the banner she rushed back to pick it up n put back on her pants then continued her walking. not b4 long she found out every1's laughing at her.................she picked up a wrong banner blown off from a nearby shop, saying 'repairing front door, back door opens'
had a big laughter w/ other boys back then n adults told us it's morally wrong n it's discrimination against rural ppl etcetc...............but now it seems it got bit virtue out of the joke:
1. undies are really for personal comfort/hygiene n keep private reproductive devices in top niche condition
2. has to be literate to identify the right banner if advertising needed
..........
ATP style is compact but loop is present and aids with racket head speed. My opinion is Compact Loop is the most efficient swing. Trying to eliminate loop is not the goal. Rather the goal is to get RHS and improve timing with a swing that is simple and compact to contact.
discussion on FHs, and timing ... I would include the following off the top of my head: My point isn't one might be better for you, but saying someone will end up a better 4.0, 4.5 with an ATP is a leap, and not based on my experience. Winning players at these levels get very good/consistent with all types of FHs ... their timing is fine.), much less needing the ESR/ISR move. Hard to make the case that a ATP fh would be easier to time for them then a more traditional classic flat fh swing. I think OP was about WTA level, so this only relevant if expanding discussion to rec players. 
), OP and the rest of us need to define 1) start of swing 2) elements from there to contact. I personally don't consider anything that happens before shoulder rotation forward the start of the swing. I also make a distinction between ATP player start of shoulder rotation and the slot. OP talks about differences in "powering start points" between ATP and WTA ... need some pics and futher discussion. Does Halep really power much from initial shoulder rotation with racquet behind her back ... or does she also have the ATP phases 1) mainly shoulder 2) mainly arm? Discuss. 
The goat knows where the ball will be at contact even before it has launched from the opponent's racquet. Sucks to be us mere mortals.If we were going to have a real
- where is typical pro and rec player "commit/calculation" point in the swing. To my surprise, my fh commit point (all calculations baked in, very little late adjustment possible) was not at the bottom of the loop/drop (certainly not the slot), but arm back but still up. I don't see how one could compare fh types timing without the context of "how we time". Tennis is dynamic ... lots of stuff built into the commit point ... like already knowing you are going to hit a cc ts fh, etc.
- what are you having to "time" ... Nadal or 4.0 USTA doubles. If Nadal, regardless of ATP harder to time or not ... moot point ... need/prefer ATP to manage the level of spin. If 4.0 ... and couldn't time a classic fh with racquet behind you and a continental grip, tennis not a good choice.
- how does one talk about "best fh for timing" without discussing topspin or not? For example ... wife's past 3.5 USTA competition was virtually spin free (occasional slicer) ... which meant they weren't swinging low to high (except lobs
- On the subject of loops, drops, gravity assist rhs (doesn't happen
Oh ... on my belief that any play at the hand/wrist (roll or extension release/forearm/racquet angle):
As @Curiosity points out ... you vary the amount of ISR in a ATP FH depending on your shot ... more ISR for bigger ts for example. Does anyone think that players max ISR swing is as easy to time as his min ISR swing? Of course not ... it's the same with low to high swngs on non-ATP FHs ... the steeper the low to high ... the more difficult to time. Topspin strokes are harder to time than flat ones ... and easier to hit dead center of stringbed with flatter stroke.
I know where I would start the discussion:
1) where is the swing calculation/commit points? Is it different for us mere mortals than Fed? (I am guessing even the GOAT does the calc with racquet back and up)
2) pics of FH start points for WTA and ATP ... bet that is not as obvious as one might think.
tagging @SystemicAnomaly for the internal FH gps system
I perform a full unit turn early. By the time I start to drop the racket head from that position, I have pretty much committed to a contact point.If we were going to have a real
- where is typical pro and rec player "commit/calculation" point in the swing. To my surprise, my fh commit point (all calculations baked in, very little late adjustment possible) was not at the bottom of the loop/drop (certainly not the slot), but arm back but still up. I don't see how one could compare fh types timing without the context of "how we time". Tennis is dynamic ... lots of stuff built into the commit point ... like already knowing you are going to hit a cc ts fh, etc.
- what are you having to "time" ... Nadal or 4.0 USTA doubles. If Nadal, regardless of ATP harder to time or not ... moot point ... need/prefer ATP to manage the level of spin. If 4.0 ... and couldn't time a classic fh with racquet behind you and a continental grip, tennis not a good choice.
- how does one talk about "best fh for timing" without discussing topspin or not? For example ... wife's past 3.5 USTA competition was virtually spin free (occasional slicer) ... which meant they weren't swinging low to high (except lobs
- On the subject of loops, drops, gravity assist rhs (doesn't happen
Oh ... on my belief that any play at the hand/wrist (roll or extension release/forearm/racquet angle) is harder to time:
As @Curiosity points out ... you vary the amount of ISR in a ATP FH depending on your shot ... more ISR for bigger ts for example. Does anyone think that players max ISR swing is as easy to time as his min ISR swing? Of course not ... it's the same with low to high swngs on non-ATP FHs ... the steeper the low to high ... the more difficult to time. Topspin strokes are harder to time than flat ones ... and easier to hit dead center of stringbed with flatter stroke.
I know where I would start the discussion:
1) where is the swing calculation/commit points? Is it different for us mere mortals than Fed? (I am guessing even the GOAT does the calc with racquet back and up)
2) pics of FH start points for WTA and ATP ... bet that is not as obvious as one might think.
tagging @SystemicAnomaly for the internal FH gps system
Yes ... when I described before my attempt at "bounce hit" with FHs ball machine:
1) unit turned but hitting arm not back yet ... around bounce
2) my version of "hit" is to think "snapshot" ... I try and take an HD pic of ball right at moment I am committed to the swing ... this turned out to be top (or near top) of backswing (so I guess arm goes back after bounce) ... note this really isn't "swing/hit" ... it's calculate/commit ... forward swing later
3) then from snapshot ... track ball as HD video (this is what I am trying to do ... my ball watching skills are lazy) ... and swing comes forward as required for calculated swing/shot.
So either I am unique/whack ... or the "1) bounce 2) hit" isn't really how we visually process, calculate and hit a tennis ball. It's more 1) see the ball at start of critical zone 2) brain and body completes the flight plan to contact.
Even if that is off ... still think we need that context in order to weigh fh types against each other regarding timing. If we are all calculating from the back of the backswing ... does WTA vs PTD change the timing much? I don't know the answer. I do see Fed still with racquet up around bounce, and other times mid-PTD-drop. So he either calculates/commits at different points, or he calcs at a the same top of backswing point all the time, and the rest is just variations of fulfilling the different flightplans.
Clear as mud? We really shouldn't use Fed to learn from ... we weren't meant to understand his fh.
"I was going to add to your reaction time thread."
You mean where I talked about " snapshot"? This wasn't my thread, but my post explaining what I was trying:
https://tt.tennis-warehouse.com/index.php?threads/any-tips-on-watching-the-ball.626275/post-12696187
I don't understand what you mean by unit turned "but hitting arm not back yet". To me, unit turn means the arms and racket are back as in the image of Roger above. And I would not wait for the ball to bounce to execute this unit turn... unless the ball bounces (short) in the service box area. If the ball bounces deep in NML, waiting for the bounce is too late to execute a unit turn. I prefer to start my unit turn about the time the ball is crossing the net... so it is already complete by the time the ball bounces.
No, I was not asking about the "snapshot" thread. Wasn't it your thread where you talk about the phenomenon of improving RT (reaction time) by viewing videos at higher speeds? That's the thread I was asking about.
Some do but I tend to discourage it. I favor a compact backswing but am ok with some who takes the racket head back even with the coronal plane or a breaking that plane a little. We shy away from excessive loops or backswings. I like Kevin G's take on the unit turn prep.
Good idea. A large teaching cart is too much for me to lug around in my EV. I normally use an 80-ball basket. They might knock over the basket with a excessive and explosive backswing. I'll sometimes put the basket there. Other times, I'll stand behind them and stick my own racket back there when they are employing a self-feed.
I don't understand what you mean by unit turned "but hitting arm not back yet". To me, unit turn means the arms and racket are back (even with his back shoulder) as in the image of Roger above. And I would not wait for the ball to bounce to execute this unit turn... unless the ball bounces (short) in the service box area. If the ball bounces deep in NML, waiting for the bounce is too late to execute a unit turn. I prefer to start my unit turn about the time the ball is crossing the net... so it is already complete by the time the ball bounces.
@ByeByePoly
No, I was not asking about the "snapshot" thread. Wasn't it your thread where you talk about the phenomenon of improving RT (reaction time) by viewing videos at higher speeds? That's the thread I was asking about.
