GCQUAD/GC2 giving extra yards on low spin shots?

[Alex Ma]

Not sure if this has already been discussed before. A few of us were talking about it in another thread so I figure we might as well start a new one talking about it. So the question is, does GCQUAD/GC2 give you extra carry yardage on low spin shots with relatively higher ball speed (120MPH and higher I think). Attached is a few of my shots as reference points. what's your thoughts?

[abirdie4me]

I’m no expert, but your numbers seem very similar to mine on my GC2. My ball speeds are usually around 145 with about 250 carry on well-struck shots, hard to tell if that is accurate to real life but does seem pretty close to how far I hit it when I do play outdoors. It seems logical to me that the ball would carry further with less spin, but I don’t really understand the physics behind it all.

[SimGolf84]

Should I be carrying the ball 307.5 yards with 164.5 mph ball speed, 14.6* launch, and 1,963 rpm backspin? Flightscope Optimizer says 277.8 yards. That was on hole 16 at Congressional with no wind for reference.

Haven't been out on a course this year so can't tell if the numbers I'm seeing on GC2 are legit or not. Can't base if off last year as I have changed my driver, ball, and have made swing changes as well.

I will say everything from 5 iron to driver seems a little inflated . The increase is welcome though after owning a Skytrak since 2015, it was very frustrating always feeling short changed after hitting driver.

[AdamV]

What’s the tee to fairway landing area elevation on hole 16?

[Baller]

Yeah, you can’t do the comparison on a course. You don’t even know the elevation change to your landing area, nor the weather conditions...too many variables.

[SimGolf84]

It says down 9", but is that to tee to fairway or tee to green?

Here are a few shots from the range.

[AdamV]

Should be for the shot you’re playing, so to the fairway, but 3 yards won’t account for the increased carry distance. 30 yards would.

[Baller]

No, not for the shot you’re playing...that is to the hole.

[mthunt]

Foresight has always been considered long on low spin shots.

[AdamV]

I’ve been doing a bit of digging since that post here a few days ago, particularly looking at some of my driver data. At face value, it does seem that for the same ball speed, launch angle and backspin, GCQ output can be 10-15 yds longer compared with a typical projectile motion model (i.e. 2D physics model taking into account gravity, drag and lift). Also compared a few shots to FlightScope Optimizer, which you can find online, and again GCQ is longer by a similar distance. I would say 5-7% longer on 220+ yd drives launching around 13 degrees and 140-150mph.

The thing that stood out for me was peak height - for the shots I compared GCQ was calculating peak height around 8-14% higher, which seems pretty material. This was not an exhaustive assessment, but it does make me wonder what sort of algorithms FS use for drag and lift during the ascent phase of the ball to achieve higher apex. You’d have to think the descent phase of the golf ball is reasonably consistent across launch monitors - the ball has stopped spinning and is largely falling with gravity and slowing down with air resistance (basic physics).

At some point I will do some outdoor testing - no wind, flat terrain and a spotter for longer shots to capture the landing location of the ball.

At the end of the day though, I’m not sure how much it matters. Irons and wedges seem accurate, which is the most important thing to me along with a good putting representation. Driver is just driver...I can still use GCQ to improve my AOA, impact and club head speed, they just won’t carry as far. Plus, longer is better for sim play

[Dax]

I’ve been doing a bit of digging since that post here a few days ago, particularly looking at some of my driver data. At face value, it does seem that for the same ball speed, launch angle and backspin, GCQ output can be 10-15 yds longer compared with a typical projectile motion model (i.e. 2D physics model taking into account gravity, drag and lift). Also compared a few shots to FlightScope Optimizer, which you can find online, and again GCQ is longer by a similar distance. I would say 5-7% longer on 220+ yd drives launching around 13 degrees and 140-150mph.

The thing that stood out for me was peak height - for the shots I compared GCQ was calculating peak height around 8-14% higher, which seems pretty material. This was not an exhaustive assessment, but it does make me wonder what sort of algorithms FS use for drag and lift during the ascent phase of the ball to achieve higher apex. You’d have to think the descent phase of the golf ball is reasonably consistent across launch monitors - the ball has stopped spinning and is largely falling with gravity and slowing down with air resistance (basic physics).

At some point I will do some outdoor testing - no wind, flat terrain and a spotter for longer shots to capture the landing location of the ball.

At the end of the day though, I’m not sure how much it matters. Irons and wedges seem accurate, which is the most important thing to me along with a good putting representation. Driver is just driver...I can still use GCQ to improve my AOA, impact and club head speed, they just won’t carry as far. Plus, longer is better for sim play

AdamV I could not agree with you more in terms of how much it matters and also that this should be an easy thing to fix. Also, not sure if there is a need for you to do your testing as this has already been done by LeoMode outdoors with his TM (I believe he has tested the result with both a GC2 as well as the GCQ). I also think all of this testing is up on his website. Thus, save yourself some time as well as the need to buy a hard hat for your friend out in the field looking to see where the ball lands and enjoy your simulated golf more

[AdamV]

I work in the mining industry, we have plenty of hard hats! And yes I saw Leo’s test v Trackman, so I won’t be rushing out to do the comparison, but it does interest me.

[Baller]

I have hit probably more shots than anyone on a quad (I believe) and it seems to play exactly how I play...even my bad shots! I do hit low spin shots sometimes and yes, they go farther, but they do in the real world as well. Personally, I think people are spending too much time on this. The only way you could say one LM is right and the other is not right is to measure them in the real world right next to each other, with marked balls, measure to the ball marks they make in the fairway and then to where they stop and in various conditions. I haven’t seen anyone do that because why would you? And how could you get perfect conditions to measure? Perhaps in an indoor football field?

TM and Foresight make the two best and they are both calculating variables. BOTH!!! IT IS A SIMULATION and they are both as close as you will find to reality.

#Whocares#Letsjustplaysomegolf

[AdamV]

Don’t disagree with you at all. The engineer in me finds the mechanics interesting, and while I do want a high level of precision given what I paid, it doesn’t need to be perfect.

[Dax]

I think we all agree that there really is no perfect system out there and for me I bought my unit knowing all of this. I am just comfortable that what I bought is great and I know about where it still needs improvement. AdamV, it is people like you that we need, as it is the curiosity that you have that does make these systems better as you are trying to identify where tweaking is needed and perhaps I was a little harsh to suggest you not repeat what LeoMode has already done as maybe you will identify some more tweaks that are needed or perhaps help FS identify variables that need correction.

[AdamV]

Thanks for the comment Dax. Certainly didn’t take any offence to your points and time will tell just how interested I get in data testing etc. Lotta golf to focus on!