Topography - The Science of Representing the Features of a Given Surface.
Lane topography in today’s bowling environment is one of the most influential factors in ball reaction. In the past, when bowling balls did not grip the lane surface as much and therefore hook as much as today’s balls, lane topography was not as much of a factor. In short, the less the amount of overall hook, the less lane topography comes into play and the more the ball hooks, the more influence topography has on ball reaction.
The topography of a lane surface consists of three different types of measurements: Crosswise Tilt, Crowns & Depressions, and Lengthwise Level. Topography affects the ball reaction characteristics on each lane and is mostly responsible for those ever present "mystery lanes" you may encounter in a bowling center.
The United States Bowling Congress makes the rules covering lane specifications. All other Federations around the world follow the USBC in this regard. One such specification is the crosswise tilt, or the measurement from gutter to gutter which shows if one side of the lane is higher than the other side. The specification is plus or minus 40 thousandths (0.040) of an inch (1.106 mm). This is just over 1/32 of an inch.
The USBC provides special lane levels used in measuring and certifying bowling lanes. For crosswise tilt the level is laid across the lane, and the bubble of the level will move to the side that is high. Feeler gauges, ranging from 0.005 to 0.040 of an inch thick, are then placed under the low end of the lane level until the bubble is once again centered. The thickness of the gauges needed equals the amount of tilt on the lane.
The majority of lanes have some amount of tilt. While there may not be consistent tilt readings across all lanes in a particular center, there is often a degree of consistency on each lane, but not always. The amount the crosswise tilts affects the entire lane can be averaged between each arrow. Example: 0.040 thousandths tilt has an average value of 0.005 thousandths for every five board area.
The crosswise tilt becomes the greatest factor when the lane is tilted to one side for a certain length of the lane. The ball is more affected by the crosswise tilt from thirty feet to the pin deck as this is where the break point is or where the ball changes direction the most. It can have some impact in the front of the lane, but the tilt needs to be pretty large. (12-15-2009 edit: Recent testing and findings have changed this notion. Testing has found that the front part of the lane has as much, if not more, influence on ball motion and direction as any point throughtout the lane. In an area of less friction, less force is required to move an object off line. Newton's Laws of Motion)
In simpler terms, if a round object is placed on a flat level surface and then one side is raised, the object roll towards the low side. Remember, this is only one of the pieces of lane surface characteristics. Below are examples of crosswise tilts:
Crosswise Tilt - High Right
Crosswise Tilt - High Left
Crowns and Depressions
The crowns and depressions show the actual shape of the surface from gutter to gutter.
A crown is an increase in height from a given zero point. The peak of the crown, of course, is the highest point. The peak, however, is not necessarily the center of the lane. It can peak at any point across the lane. A crown, unlike crosswise tilt, is measured by the amount of change across each five-board area. This is also measured using the lane level with an attachment called the Dial Indicator. The indicator glides across the level reading the amount of rise or drop of the surface in thousandths of an inch. (12-15-2009 edit; with the invention fo the Kegel Lane Mapper, topography is now measured on each board instead across a five-board area.)
A crown can give the bowler a sense of hold but also takes away swing area. Like crosswise tilt, crowns have more influence when they remain consistent across a certain length of the lane. Crowns have a tendency to benefit players that do not cross a lot of boards. Two units of oil can feel like five units when the lane is crowned. The amount of pressure that the ball has against the lane is less when going away from the pocket but greater when more direct. It is like riding over a hill.
Example of a 0.040 inch Crown
A depression is the opposite of a crown. The shape is measured by the amount of decrease from the zero point. This concave shape allows bowlers to feel that there is more swing area but less hold. It can make a line near the gutter have more swing area. Basically, five units of oil can react more like two units of oil.
A depression can also force players to cross an increase number of boards. The pressure the ball feels on a depression is greater when crossing boards which increases friction between the ball and the lane. But a ball thrown on a more direct trajectory will have trouble reaching its break point because of this increased friction.
A depressed lane is very much like a banked turn on a race track. When an automobile or motorcycle hits the banked curve, it becomes easier to turn and also slows easier. The momentum of the vehicle is now compressed into the embankment.
Example of a 0.040 inch Depression
The USBC specifications for crowns and depressions are the same as crosswise tilt, plus or minus 0.040 of an inch.
Crosswise Tilt + Crowns + Depressions readings at a distance of 42 feet from the foul line.
The lengthwise level of the lane is the final piece in the topography puzzle. This can also have dramatic effects on ball reaction. This allows us to see how many hills and valleys the ball sees rolling down the lane. Like driving, the vehicle maintains or even increases speed when moving down a hill. It slows quite a bit when moving uphill. A lane that runs uphill or downhill from 30 feet to the pindeck will become more sensitive to speed changes. This is caused by the amount of surface pressure that the ball has against the lane. A lane going downhill can play tighter and an uphill lane can promote more hook.
Most lanes are installed using a carpenter’s string or a laser. One problem with a carpenters string is it will tend to show the lane is lower in the center than at the foul line and pin deck. In our data collection process we collect the lengthwise measurements every five feet, with a laser.
Example of a lane’s lengthwise level taken every 3.5 feet:
When all three factors (crosswise tilt, crowns and depressions, and lengthwise level) are added together, many different things can happen. Each lane has some differences whether it is one or all of the three factors. Certain combinations of the three can have somewhat similar characteristics as a lane that has a different topography. Inequity can be seen in a surface and the level of a lane can give a certain style or side an advantage.
The patterns run for most high level competitive bowling events allow the topography to stand out. The patterns themselves normally do not provide much swing area or hold area, so we have an idea of what the reaction should look like. When we see something different, we could make the conclusion its the topography. It might also the way the players you are following are breaking down the oil pattern, but that is another discussion for another day.
Believe it or not, wood lanes tend to be the most consistent across a given center. The reason is the sanding equipment does not allow for significant changes from lane to lane. Most lane resurfacing machines have a fixed pattern for making cuts during the resurfacing process. But keep in mind, there can still be mystery lanes.
On the other hand, most would think synthetic lanes are the flattest surface currently on the market, but that is far from the truth. Lanes made up of multiple synthetic panels can, and are the majority of the time, be vastly different from lane to lane across a house. There are many reasons for these inconsistencies with synthetic lanes.
Reason #1: The Weather
Centers located in areas of the world that can experience large temperature and humidity changes from season to season, see the most changes in topography (both wood and synthetic). Even though the lanes are synthetic, they are still made of wood in one form or another. Substructures are made of a pressed board, and pressed fiberboard's (wood fibers). The actual surface is made up of sheets of pressed paper with a melamine layer that the ball touches. So the surface can absorb moisture from the air and it can dry out when the air is dry. All wood does this!
Reason #2: The Installation
How synthetic lanes are installed is very important. They may initially be consistent across the house. Eventually the lane takes abuse and gets exposed to environmental factors, explained above. Remember that a wood lane is one solid piece while the synthetics are separate pieces screwed together. An installer may tighten screws tight enough to dimple the surface and cause the areas not screwed down to "bubble" up.
All of these factors make up the topography of a particular lane surface which can and probably will influence the reaction of your bowling ball.