（樓下有朋友要談談網球，俺在這方面稍有體會，算拋磚引玉吧）
現在喜歡網球的人不少，大部分的朋友雖然打了很久的球，但很少有人真正知道自己到底是一個什麼樣的水準。
網球不僅是娛樂，也是一項技巧性非常非常高的競技項目。大部分愛好者只停留在底線抽殺的練習階段，而很少打Game。要知道即使你能在正手和反手和你的球伴在練習是抽１０個來回Top spin，並不意味着你在Game里能保持一貫的Consistency。網球的規則，場地和球的速度決定的它是力量和技巧性的高度統一。力量意味着主動，而技巧則是對場地的充分利用。如果大家有機會看阿加西打球，就會發現他對場地的利用以到了出神入化的地步。這就是年過３０力量並不在優勢的阿加西能高居ATP排名第一的原因。
網球的主要技術有正反手上旋抽殺（top spin),削球（Slice)，截擊（volley)，接發球，高空球等。針對不同的技術，握拍（Grip)的方法也不同。比如top spin用東方式為好，而發球和截擊可採用大陸式。對於初學者，第一步要掌握的就是正確的握拍。握拍也是很多網球愛好者容易疏忽的地方。很多人說為什麼我就打不出漂亮的上旋呢，現檢查一下你的握拍吧。
既然網球是一項競技，網球水平的提高還得靠實戰。實戰和練習完全不同。舉個例子：如果你在練習中第一發球的命中率有５０％，在實戰中你會全部miss掉。而且只有在實戰中才能找到各種不同球的落點的感覺，從而迅速提高你的consistancy。在網球中，Consistancy是衡量水平高低的重要指標。
說了這麼多，現在規入正題。圍棋有段位，柔道有分級，對於網球水平的評估也有標準。US tennis association leagues有一個NTRP(national tennis rating program)。這是一個美國的國家標準，主要適用於從業餘學者，中級水平，高校水平甚至能判斷是否具有職業水準。
規則分為七級，以阿拉伯數字標識。每級之間另有半級作為過渡用。如果你第一次拿起網球拍，踏進球場你就是１.0。如果你做空中飛人靠參加國際大賽掙獎金為生，那麼你是世界級的選手，你的NTRP的級別是最高級７.0。當然這個7.0對你已沒有任何意義，你得靠世界排名來證明自己。可以這麼說，NTRP對業餘者意義更大。對照它，你可以知道該向那方面努力才能到更高的水平。
１.0 到２.5: 初學者，習慣於正手擊球，不喜歡反手；不能適當地上網截擊。沒有consistency，拋球（toss)沒有consistancy，基本不會接發球。
３.0 到3.5：這時大部分有一定球齡愛好者集中的水平段。已能夠自由使用正反手，能控制方向，有上網截擊的意識，對中等力量的球有良好的consistancy。 發球以開始控制落點和力量，能接住中等力量的發球。
4.0到５.0：開始進入業餘高手的行列。好比圍棋的業餘一，二段（不恰當的比喻：）。正反手能有效利用速度和旋轉；能很好地控制擊球深度。上網截擊步伐良好，能控制截擊的方向和深度。發球能利用力量和旋轉，極少有發球雙誤。
5.0到５.5: 已經是相當高的業餘選手了。力量和consistency已成為武器。能夠發現和分析對手的弱點，在競爭中有良好的策略。
６.0到7.0：６.0級別基本上已是college level的水平，通常在地區和全國有排名。7.0指的是職業選手。
大概說了一下US NTRP的標準，朋友們可以對照一下自己在哪一段。如果認真一點的話，不妨請一個網球coach鑑定一下。這一篇拋個磚，希望看到更多關於網球的文章。
附錄：
Complete NTRP Scale
NATIONAL TENNIS RATING PROGRAM
Verification Guidelines
1.0
This player is just starting to play tennis
1.5
This player has limited experience and is still working primarily on getting the ball into play
2.0
FOREHAND: Incomplete swing; lacks directional intent
BACKHAND: Avoids backhands; erratic contact; grip problems; incomplete swing
SERVE/RETURN OF SERVE: Incomplete service motion; double faults common; toss is inconsistent; return of serve erratic
VOLLEY: Reluctant to play net; avoids BH; lacks footwork
PLAYING STYLE: Familiar with basic positions for singles and doubles play; frequently out of position
2.5
FOREHAND: Form developing; prepared for moderately paced shots
BACKHAND: Grip and preparation problems; often chooses to hit FH instead of BH
SERVE/RETURN OF SERVE: Attempting a full swing; can get the ball in play at slow pace; inconsistent toss; can return slow paced serve
VOLLEY: Uncomfortable at net especially on the BH side; frequently uses FH racket face on BH volleys
SPECIAL SHOTS: Can lob intentionally but with little control; can make contact on overheads
PLAYING STYLE: Can sustain a short rally of slow pace; weak court coverage; usually remains in the initial doubles position
3.0
FOREHAND: Fairly consistent with some directional intent; lacks depth control
BACKHAND: Frequently prepared; starting to hit with fair consistency on moderate shots
SERVE/RETURN OF SERVE: Developing rhythm; little consistency when trying for power; second serve is often considerably slower than first serve; can return serve with fair consistency
VOLLEY: Consistent FH volley; inconsistent BH volley, has trouble with low and wide shots
SPECIAL SHOTS: Can lob consistently on moderate shots
PLAYING STYLE: Consistent on medium-paced shots; most common doubles formation is still one-up, one-back; approaches net when play dictates but weak in ????ution
3.5
FOREHAND: Good consistency and variety on moderate shots; good directional control; developing spin
BACKHAND: Hitting with directional control on moderate shots; has difficulty on high or hard shots; returns difficult shot defensively
SERVE/RETURN OF SERVE: Starting to serve with control and some power; developing spin; can return serve consistently with directional control on moderate shots
VOLLEY: More aggressive net play; some ability to cover side shots; uses proper footwork; can direct FH volleys; controls BH volley but with little offense; difficulty in putting volleys away
SPECIAL SHOTS: Consistent overhead on shots within reach; developing approach shots, drop shots; and half volleys; can place the return of most second serves
PLAYING STYLE: Consistency on moderate shots with directional control; improved court coverage; starting to look for the opportunity to come to the net; developing teamwork in doubles
4.0
FOREHAND: Dependable; hits with depth and control on moderate shots; may try to hit too good a placement on a difficult shot
BACKHAND: Player can direct the ball with consistency and depth on moderate shots; developing spin
SERVE/RETURN OF SERVE: Places both first and second serves; frequent power on first serve; uses spin; dependable return of serve; can return with depth in singles and mix returns in doubles
VOLLEY: Depth and control on FH volley; can direct BH volleys but usually lacks depth; developing wide and low volleys on both sides of the body
SPECIAL SHOTS: Can put away easy overheads; can poach in doubles; follows aggressive shots to the net; beginning to finish point off; can hit to opponent's weaknesses; able to lob defensively on setups; dependable return of serve
PLAYING STYLE: Dependable ground strokes with directional control and depth demonstrated on moderate shots; not yet playing good percentage tennis; teamwork in doubles is evident; rallies may still be lost due to impatience
4.5
FOREHAND: Very dependable; uses speed and spin effectively; controls depth well; tends to overhit on difficult shots; offensive on moderate shots
BACKHAND: Can control direction and depth but may break down under pressure; can hit power on moderate shots
SERVE/RETURN OF SERVE: Aggressive serving with limited double faults; uses power and spin; developing offense; on second serve frequently hits with good depth and placement; frequently hits aggressive service returns; can take pace off with moderate success in doubles
VOLLEY: Can handle a mixed sequence of volleys; good footwork; has depth and directional control on BH; developing touch; most common error is still overhitting
SPECIAL SHOTS: Approach shots hit with good depth and control; can consistently hit volleys and overheads to end the point; frequently hits aggressive service returns
PLAYING STYLE: More intentional variety in game; is hitting with more pace; covers up weaknesses well; beginning to vary game plan according to opponent; aggressive net play is common in doubles; good anticipation; beginning to handle pace
5.0
FOREHAND: Strong shot with control, depth, and spin; uses FH to set up offensive situations; has developed good touch; consistent on passing shots
BACKHAND: Can use BH as an aggressive shot with good consistency; has good direction and depth on most shots; varies spin
SERVE/RETURN OF SERVE: Serve is placed effectively with the intent of hitting to a weakness or developing an offensive situation; has a variety of serves to rely on; good depth, spin, and placement on most second serves to force weak return or set up next shot; can mix aggressive and off-paced service returns with control, depth, and spin
VOLLEY: Can hit most volleys with depth, pace, and direction; plays difficult volleys with depth; given opportunity, volley is often hit for a winner
SPECIAL SHOTS: Approach shots and passing shots are hit with pace and a high degree of effectiveness; can lob offensively; overhead can be hit from any position; hits mid-court volley with consistency; can mix aggressive and off-paced service returns
PLAYING STYLE: Frequently has an outstanding shot or attribute around which his game is built; can vary game plan according to opponent; this player is 'match wise,' plays percentage tennis, and 'beats himself' less than the 4.5 player; solid teamwork in doubles is evident; game breaks down mentally and physically more often than the 5.5 player
5.5
This player can hit dependable shots in stress situations; has developed good anticipation; can pick up cues from such things as opponent's toss, body position, backswing, preparation; first and second serves can be depended on in stress situations and can be hit offensively at any time; can analyze and exploit opponent's weaknesses; has developed power and /or consistency as a major weapon; can vary strategies and style of play in a competitive situation.
6.0 to 7.0
These players will generally not need NTRP ratings. Rankings or past rankings will speak for themselves. The 6.0 player typically has had intensive training for national tournament competition at the junior level and collegiate levels and has obtained a sectional and/or national ranking. The 6.5 player has a reasonable chance of succeeding at the 7.0 level and has extensive satellite tournament experience. The 7.0 is a world class player who is committed to tournament competition on the international level and whose major source of income is tournament prize winnings.
