This week, at the PGA Tour’s WGC-Mexico Championship, we are going to watch some of the best and longest players on the planet play what will effectively be one of the shortest courses on tour.

Now, 7,341 yards is by no means a cakewalk, and there are shorter courses from a pure yardage perspective played on tour—Harbour Town, as an example, only plays at 7,099 yards from the very back. The difference is Harbour Town is played at sea level while Club de Golf Chapultepec is at over 7,500 feet of elevation, and when you factor in the altitude difference between the two courses, they play very differently—more on the math in a moment.

The altitude will also factor in how some players will be setting up their equipment and we could see some adjustments. The most obvious is lofting up the driver or fairways woods to increase carry, which is something Tiger Woods specifically mentioned last year.

The biggest misconception when talking about playing golf at altitude is that the ball doesn’t spin the same in thinner air and players “loft up” to maintain spin. Let’s get into the physics to bust this “spinning less” myth and simplify the science behind playing at altitude,

The golf ball is an inanimate object, and it has no idea it’s at altitude; the air will not have an impact on how much the ball will actually spin. Yes, increasing loft should, by almost every imaginable measure, increase spin but the air it travels through will not change the spin rate.

However, playing at altitude has an effect, Let’s break down what happens

• Thinner air exerts less drag force (resistance/friction) on the ball. The ball moves more easily through this less dense air and won’t decelerate as quickly as it flies. But note that the faster an object moves the more drag force will occur
• Less resistance also means that it is harder to shape shots. So you when you see Shot Tracer, the pros are going to be hitting it even straighter (this makes Tiger’s fairway bunker shot last year even more unbelievable)
• Less force = less lift, the ball will fly lower and on a flatter trajectory

Time for some math from Steve Aoyama, a Principal Scientist at Titleist Golf Ball R&D (full piece here: The Effect of Altitude on Golf Ball Performance)

“You can calculate the distance gain you will experience (compared to sea level) by multiplying the elevation (in feet) by .00116. For example, if you’re playing in Reno, at 1 mile elevation (5,280 ft.) the increase is about 6% (5,280 x .00116 = 6.1248). If you normally drive the ball 250 yards at sea level, you will likely drive it 265 yards in Reno.”

Not every player will be making changes to their bag, and some will instead focus on the types of shots they are hitting instead. When speaking to Adam Scott earlier this week, I was able to ask if he planned on making any changes heading into Mexico the week after his win at the Genesis Invitational.

“It’s very rare for me to make club changes week-to-week beyond playing in the Open Championship and adding a longer iron. The one thing I focus on when playing at altitude is avoiding partial shots where I’m trying to reduce the spin because as spin goes down the ball doesn’t want to stay in the air. I’ve experienced partial shots with longer clubs that end up 25 yards short, and because of that I want to hit as many full shots as possible”

With Club de Golf Chapultepec sitting just over 7,800 feet above sea level, we’re looking at 9.048 or an increase of just over 9 percent. That makes this 7,341-yard course play 6,677 yards (+/- where the tees are placed).