Why does one 300g racket spit the ball out with heavy topspin while another, same weight, same head size, seems to hold on to it? Nine times out of ten the answer sits in a pair of numbers most people skip past on the spec sheet: 16x19, or 18x20.
Here are the questions we get asked across the counter about string patterns, in the order they usually arrive.
What do the two numbers mean?
The first number is the count of main strings, which run from the handle up to the tip. The second is the count of cross strings, which run side to side. A 16x19 frame has 16 mains and 19 crosses. An 18x20 has two more mains and one more cross, packed into roughly the same hoop, so every gap between strings is smaller.
That is the whole difference: how much space each string has to move. Everything people say about spin, control, feel and durability comes out of that one fact.
Two frames sharing the same numbers can still differ, because spacing is not always even. Some 16x19 layouts fan the mains wider towards the top of the hoop, where you tend to make contact on a topspin forehand, and some 18x20 frames spread theirs enough to feel more open than the count suggests. The numbers are a good guide rather than a full description.
Does an open pattern really produce more spin?
It helps, but it does not create spin on its own. Spin comes from racket head speed and the path your swing takes through the ball. What an open 16x19 does is let the main strings slide sideways on impact, bite into the ball, then snap back into place and drag the ball as they go. More space means more movement, more bite and a steeper launch angle.
A dense 18x20 holds the strings roughly where they started. Contact is more uniform across the string bed, the ball flattens against it rather than sinking in, and the launch angle is lower. You can still hit heavy topspin with an 18x20. You just do more of the work yourself, and the ball tends to come off flatter and faster.
Which pattern goes through strings faster?
The open one, comfortably. Every time a main string slides across a cross string it saws a small notch into it, and the more the strings move, the quicker those notches cut through. A player who breaks strings monthly in a 16x19 will often get noticeably longer out of the same string in an 18x20.
If breakage is your main frustration, though, the pattern is only one lever. Gauge matters too, and so does the material. A thicker gauge or a tougher string from our tennis string range will usually buy you more time than switching frames will.
Does the pattern change how the racket feels?
Yes, and this is the part people notice within three shots rather than three months. An open pattern feels softer and more elastic. The ball seems to sit on the strings a fraction longer, which some players read as comfort and others read as vagueness.
A dense pattern feels firmer and more connected. There is less trampoline, more of a clean thud, and the response is more consistent from one shot to the next. That firmness can be less kind on the arm, particularly with a stiff polyester string in a stiff frame.
Should the string change when the pattern changes?
Usually, yes. The two decisions belong together. In a dense 18x20, a thinner gauge, a softer multifilament, or a few pounds less tension will restore some of the bite and comfort the pattern takes away. In an open 16x19, a durable string at a slightly higher tension keeps the ball from flying and slows the notching.
What will not fix anything is hardware. A dampener changes the sound and very little else, so if you are browsing tennis accessories hoping to solve a launch angle problem, save your money and change the string instead.
So which pattern suits which player?
Broadly, and with the usual caveat that individuals beat categories:
- 16x19 suits players with long, fast, upward swings, semi-western or western forehand grips, and a baseline game built on shape and margin over the net. It is the pattern most modern club singles players get on with.
- 18x20 suits flatter hitters, players who take the ball early, big first servers, and doubles players who want a predictable block return. It also suits anyone who values knowing exactly where the ball is going more than they value an extra 200rpm.
Head size and weight muddy this a little. An 18x20 in a 100 sq in frame has more room between strings than an 18x20 in a 95, so it will feel less locked down than the count implies. Judge the frame as a whole rather than the pattern in isolation.
Neither is the advanced option. There are club players who would be far better served by an 18x20 and are fighting a 16x19 because it is what the sponsored professionals use on television.
Is it worth switching frames over?
Not as a first move. If the ball is flying long, try two or three pounds more tension before you look at a different racket. If you want more spin, look at your swing path and your string before your string pattern. Changing pattern means changing racket, and a racket is the most expensive way to fix a problem that a restring might have solved.
When you do decide to try the other side, hit with both on the same day, with the same balls, and hit some returns as well as rally balls. Patterns feel very different when you have not chosen the shot.