Green Speed - Stimpmeter
그린스피드 -스팀프미터
The faster the green speed, the easier the putting, and the more opportunities there are to lower your score.
Green speed measurement, Stimpmeter
스팀프미터는 미국 골퍼 에드워드 스팀프슨(Edward Stimpson)에 의해 처음으로 개념적으로 제작된 것으로 1935년 US오픈에서 사라젠의 퍼팅이 그린을 한참 벗어나는 것을 보고, 그린 스피드를 객관적으로 측정하는 방법을 고안해 냈다. 그 후 1976년 프랭크토마스가 알루미늄으로 제작한 것이 미국골프협회(USGA)에 의해 US오픈에서 처음 사용됐다. 1978년부터는 USGA가 공식 그린 스피드 측정 장비로 지정했다.
스팀프미터는 길이 36인치 (91㎝), 폭이 1.75인치 (4.4㎝)에 145도의 V자 형태로 생겼습니다. 아래 끝에서 30인치 (76㎝) 되는 곳에 홈이 파져 있는데 이곳에 골프공을 올려놓고 다른 한쪽을 그린에 대고 서서히 들어 올리면 약 22도의 경사에서 골프공이 중력에 의해 그린 위로 굴러 내려가게 됩니다.
- 3개의 공의 평균거리로 스피트 측정 : 3개의 공의 오차 범위는 직경 20cm이내의 범위
- 마찬가지로 반대편에서 3개의 공의 평균거리 측정
- 최종적으로 측정된 양방향의 평균거리로 그린스피드 측정
그린스피드는 골프장마다 차이가 있으나, 보통 2.8m를 기준으로 한다. 평상시 그린스피드는 2.7 ~2.9m사이를 유지하지만, 정식대회 때는 3.5m까지 그린스피드를 맞춘다. US Open메이저대회의 경우 4.0m까지 셋업하여 '유리그린'이라고 알려져 있다.
습기가 많은 아침과 저녁엔 상대적으로 그린 스피드가 느려진다. 오전엔 그린이 점점 건조해지면서 스피드가 빨라지는 경향이 있다. 날씨가 건조하면 역시 빨라진다. 계절에 따른 차이도 크다. 잔디의 성장이 멈춰있는 초겨울부터 봄까지가 그린 스피드가 가장 빠르다. 잔디가 한창 자라기 시작하는 5월부터 여름까지는 상대적으로 스피드가 느려진다.
그린스피드 관리
5 Factors That Affect Green Speed
1. Length of grass 2. Firmness of green ground 3. Moisture and grass texture 4. Aeration 5. Length of grass growing in the afternoon
If the green is the most important part of the golf course, golfers consider green speed to be the most important. Generally, when it comes to increasing green speed, we think of several tasks such as foreshadowing and rolling, but there are more important factors that affect green speed.
environment
Water drainage, air flow, sunlight, etc. ultimately affect the environment surrounding the grass, or weather, which has a significant impact not only on the growth of the grass but also on the green speed.
Open greens, which allow light and air to enter, are compared to closed and shaded greens, and open greens provide better turf conditions and speeds. Likewise, the wettest and driest greens on a course can vary greatly. Therefore, evaluating the environment around each green is the first step toward maintaining consistent green speeds.
Environmentally, to increase green speed, you can consider opening up space to increase sunlight and wind in the east and south directions, such as removing trees and shrubs.
If tree removal is not possible and budget allows, blowers or lighting equipment can be used. In some cases, a good drainage system may also be required.
To naturally improve green speed, it is recommended to improve the grass growing environment.
stiffness
A solid, dry surface with good drainage is required to achieve sustainable green speed all year round.
This requires drainage that can maintain humidity below 30% all year round, but such greens are hard to find.
Therefore, most of them maintain drainage capacity by improving surface moisture, light, air, soil layer, and organic matter management through soil improvement and installation of various drainage systems.
Growth rate and density
Tight, lush greens may look attractive, but green speeds are definitely reduced.
High growth and density of grass slows down the ball by causing friction or drag. Slow-growing, low-density grass is ideal, and it dries the surface more easily after rain, creating a firm, dry green.
Therefore, in order to obtain a fast green speed, it is necessary to control excessive growth of grass. Care should be taken to control fertilization and irrigation, and the cutting height should be adjusted according to the season.
However, sometimes the weather causes the grass to grow in an undesirable direction, requiring a renewal procedure such as a verticut.
Generally, an appropriate grass density is defined as the degree to which the space around the grass can be seen and the topsoil can be seen.
Precognition and Rolling
To maintain green speed, periodic mowing is necessary. Also, shaded and wet greens for long periods of time are soft and not suitable for mowing. Rather, drainage conditions and air flow should be considered more. Mowing wet greens will cause wheel marks and reduce smoothness, accuracy, and surface quality because the surface is soft. Therefore, it is important to mow the greens under ideal growing conditions.
For the quality of the cutting, a self-propelled greens mower is used, and the blades must be set correctly so that the grass blades are cut cleanly. To achieve this, the blades must be wrapped periodically, and this must be done especially if topdressed regularly.
Lower cutting heights will provide higher green speeds, at least initially. However, continuous cutting lower will reduce root depth and increase the likelihood of foreign grasses entering, which can lead to poor quality. Therefore, controlling grass growth and creating a moderately firm and dry surface, rather than simply cutting lower, allows for more sustainable green speed management.
Rolling improves green speed, smoothness, and accuracy, but the green speed improvement from a single roll is not constant throughout the day, so it is only an auxiliary means of short-term speed improvement.
If the green speed is continuously measured and digitized, it is necessary to set a realistic management level of green speed. Rather than increasing the maximum green speed without considering the condition of the grass, it is better to manage it in the direction of maintaining a constant speed throughout the operating hours. Rather , it may be right to focus on increasing the average green speed by increasing the minimum speed and manage it in the direction of reducing only the speed difference between each green.
