You know how far you hit your 7-iron. But that distance applies on a calm, flat day at 20 degrees. On the course it is almost never like that. A headwind, a green that sits higher, a cold morning: they all make the shot longer than the number on the marker. A few rules of thumb get you a long way.
Wind: a headwind costs more than a tailwind gives
A widely used rule of thumb: into the wind, add about 1% per mile per hour of wind; downwind, take off about 0.5%. Converted to kilometres:
- Headwind: about 0.6% longer per km/h of wind. In a 20 km/h headwind the shot plays roughly 12% longer.
- Tailwind: about 0.3% shorter per km/h of wind. In a 20 km/h tailwind the shot plays roughly 6% shorter.
So a headwind works about twice as hard as a tailwind. A high ball with lots of spin, such as a wedge, suffers even more than a low ball.
Crosswind
A crosswind pushes the ball sideways. How much depends on the wind strength, how long the ball is in the air and how high it goes. A fixed rule is hard to give. Aim into the wind, and remember that a miss in the direction of the wind gets bigger.
Elevation: about a metre per metre
If the green sits higher than where you stand, the shot plays longer. The rule of thumb: add about one metre per metre of elevation, and take off a metre for every metre the green sits lower. The Netherlands is flat, but on courses with hills and dunes the difference can reach 5 or 10 metres, and then it soon makes a club's difference.
Temperature: cold air is "thicker"
Cold air is denser, so the ball slows down sooner. Rule of thumb: about 1.5% less carry for every 11 degrees colder than 21 °C. On a 5 °C morning you hit about 2% shorter. That sounds small, but on a 150-metre shot it is over 3 metres.
Worked example: 150 metres to the flag
| Situation | Plays like | Difference |
|---|---|---|
| Calm, flat, 21 °C | 150 m | – |
| 20 km/h headwind | approx. 168 m | +18 m, well over a club more |
| 20 km/h tailwind | approx. 141 m | −9 m |
| Green 5 m higher | approx. 155 m | +5 m |
| Green 5 m lower | approx. 145 m | −5 m |
| 5 °C | approx. 153 m | +3 m |
| 20 km/h headwind, 5 m higher, 5 °C | approx. 176 m | +26 m, about two clubs more |
The effects add up. Precisely when they all work in the same direction, going by the number on the marker alone easily leaves you two clubs short.
Why rules of thumb are not enough
Rules of thumb are averages. In reality the effect depends on your own ball flight: a player with a high, spinning ball loses more in the wind than someone who hits it low. And on the course you still need to know how hard the wind is blowing, from which direction, and how much higher that green really is. The naked eye often gets that wrong.
How CaddiQ works it out. For every shot CaddiQ uses:
- the current wind at your location, in strength and direction, relative to the line of your shot;
- the height of your ball and of the target, from an elevation model of every hole;
- the temperature and air pressure at that moment;
- your own distances per club, adjusted with the shots you actually hit.
From that follow the club, the target and how far to aim away from the flag to play away from the danger. You see it at a glance on your phone. Try it free, or see which courses it works on.
Note: in a qualifying round or competition you may not use a device that measures elevation changes or wind (Rule 4.3). You can of course always use the rules of thumb in your head.