Technical Information

Some bowl models subtract bias as they run down the green. This effect is shown on the test table for comparison of bowl sole types..see faq below showing self-correcting "balanced or uniform arc sole" type bowl taking same line both wobbled and normal upright delivery. Ideal for any NZ greens. The red line shows the path of a wobbled "un-balanced sole" or "variable arc geometry sole" type bowl going narrower than normal.

The narrower path is what you get on the green with normal upright delivery. It is important to select the right bowl model/type for your game, see check list and explanation in faq below.

Points to remember:
A bowl is only "reading" the green and acting accordingly. Sometimes a wider draw set will go very narrow especially on a heavy or wet green and a narrower running model can sometimes have a lot more turn at the finish than it would on a hard and fast green. You may also experience a much wider draw on the forehand than normal and almost no draw on the backhand, usually caused by cross-wind and angles will change playing from the other direction.
Various playing surfaces can have your bowls doing something different to normal when they are heavy.

Also "very narrow running" models marketed over recent years are not narrow biased on the test table, they take as much or more bias as the Test Bowl and then subtract bias when played on a green, i.e. they take less bias than the Test Bowl on the green. They are given legal status as World Bowls standardised testing to be only done on a table. This means testing can only be done in 3 countries, Scotland, England and Australia, our NZ table being currently unregistered.
In general these narrow running models have difficulty in subtracting exactly the same amount of bias on every delivery and getting consistent turn-in at the head on NZ greens.
Drakes new technology overcomes this problem and display very good winning consistency.

If you are new to the game of bowls there is a lot of info to catch up on. Bowls are not all the same....black or brown and round and there have been a lot of changes recently. Drakes Pride have recognized a problem that many players in NZ have found when purchasing bowls while travelling in Australia, after playing a few months back home at their club they're having consistency problems. The bowl suffers from inconsistent turn-in at the head, what went great in Aust doesn't in NZ.
Our greens are different and in some cases not high quality and are probably the fastest in the world. To make matters worse some clubs with normally very good green quality are experiencing problems over past years with noticeable deterioration. Some players who have joined the "go narrow"club have found their bowling is now hot and cold, and some have been told by administrators to purchase "narrow running bowls" to get into rep teams.

The technical part:
If 2 different models have the same bias on the test table but then 1 has only 50% of that table bias on the green, the narrower bowl has to negate or subtract the other 50% as it goes. Something has to be different in the engineering of the 2 sets. Herin lies the problem. In order to take a consistant 50% bias line and turn-in there has to be consistent bias read from the green onto the bowl to get the same 50% on every delivery. If a bowl changes to subtracting 60% of its stated bias then it will take a narrower line and won't arrive at the jack as intended. This usually makes the player adjust the line on the next delivery which switches back to 50% and again has the bowl finishing on the other side of the head in the wrong place. Players are making line changes based on where the last bowl finished and in this example line direction was never the problem, it's green conditions that's giving different bias percentage on different deliveries. Delivery, green quality, grass type and especially windy weather conditions have a marked effect on this bias-subtraction bowl type. It's reasonable to assume the game is easier to play with very narrow running bowls,. Not true, they come with "strings attached" having their own set of difficulities to overcome and generally play much better indoors.

Frequently Asked Questions

Q. Why are some bowl models much easier to play, why do some models go so narrow but play so erratically and are they really legal?

A. This is the most asked question/s and can be a bit confusing.
All bowls are currently considered legal as defined by the Rules if they have at least minimum legal bias as set down by World Bowls and group within 100mm on a test table. But due to the sole shape engineering many recent models take much less bias on the green than is present during table testing. These models subtract or negate bias as they run down the green, the Test Bowl does not. This is a fairly recent development that has come into the game since comparison with the Test Bowl on a green was dropped in favour of only table testing and with no wobble test done either. This would have shown the amount of bias subtraction that happens on the green..see pic above showing wobbled bowl not having even min bias and finishing well short of the white pass line. Older model bowls pass the min bias line when delivered normally and when wobbled. The current narrow-running sets only pass the un-wobbled test. We get many comments about bowls now being just skittles and is the subject of much concern.
So how does it all work?

Basically there are 2 types of bowls, non sole-shape sensitive and sole-shape sensitive based on the shape of the crown which could be descibed as self-correcting or "balanced arc, or uniform shape sole"' and non self-correcting "un-balanced arc or variable geomertry sole shape" In the pic above there are the blue lines showing the track down the test table of Drakes Professional and Ultra, both "balanced-uniform arc" type models. Both normal and wobbled delivery have taken almost the same line since the bowl recieves the same intructions to take it's normal bias regardless of which part of the bowl's sole is touching the table or green. Clearly, when wobbled the sole is averaged out and a greater amount of the bowl's running surface touches the ground as it oscillates through an arc of say 12-14 degrees. The arc shape across the centre of the bowl is like a piece of a circle, it is a constant uniform arc. It doesn't matter which part of that bowl arc is touching the green, it will take it's normal stated bias the makers have set into it, the same bias as seen on the test table. If the bowl wobbles at delivery, it doesn't change it's line. This bowl type is extremely stable and very regular in it's behaviour and will withstand irregular delivery or windy or bumpy green conditions.
[The white line is the WB min bias pass line. Bowls delivered without any wobble must be at this mark or cross it to the right and group in a circle of 100mm to be be legal; clockwise test]

Sole shape and effect explained: [ simplified ]

Some bowl models will go narrower when wobbled and the sole shape or type is then displayed. Most of the old sets did this but had so much bias that they still went quite wide even with some bias-subtraction happening. If this happens it has a dual-sole or split-running sole i.e the arc of the sole that touches the green is made up of 2 different shapes joined together. We could call them A at the apex and B on either side. The A part at the apex tells the bowl to turn and the B part tells it to go straight. Neither win out so a compromise is made as to the actual bias path on the green and some bias subtraction happens.
On the test table only part A touches and shows all its bias. On the green both A & B touch and so the bias-subtraction part kicks in. The difference is in the size of the footprint contact between the table material and the green, like between your kitchen lino and carpet in the lounge.
The only way to see the final green result on a table is to wobble the bowl which averages out its sole shape, at present disregarded as part of the test and not needed during the years of greens testing. Please be aware there is currently no "on-the-green minimum bias standard" in the Sport of Bowls as a result of the dropping of greens testing and adopting table only testing.

The "variable geometry arc" type has the advantage of being made to take different tracks down the green and go narrower than stated bias, play the weighted knock-on shot a little better but can suffer in adverse conditions as many bowlers can attest to with models sold here over past few years that simply don't play well outdoors, i.e. you get varied results due to the sole geometry. You either play the odd brilliant game or just plain terrible, consistency is hard to come by. The biggest problem is the greens we have in many parts of New Zealand and sand filled synthetics that won't allow some bowl models to take consistent lines down the green and have consistent turn-in at the finish. The balanced sole bowl overcomes these problems but can't be made to take the very narrow line down the green that some players want or have been told to buy to get selected in top teams or rep play. Our new models Direct, Corsair and Delta give players the choice of flatter finish bowls that overcome the wandering tendancies discussed above.

Q. Which model/track should I use?
A. Depends on the type and speed of the green and to some extent your skill level. As discussed above there are some technical differences that make the Ultra, Professional and Delta easier to use and more forgiving than other bowl models and play extremely well on bumpy astro sand type greens.
The Drakes Ultra model takes a banana arc to the jack and is good for greens running 15-16.5 seconds.

The Professional takes a narrower hockey-stick line but comes into the head at a similar arc/angle to the Ultra and is slightly more weight sensitive.
The Delta goes a little narrower than the Professional and is very stable in most conditions and is recommended for greens 16-17 seconds. The Corsair adds to this by holding a straighter line for a longer distance before entry to the jack, and is recommended for 17-19 sec greens. The Direct takes this 1 step further. Ideally these narrower models should be your alternative set if you play on a wide range of green speeds and conditions.

In general the trend in the last few years is towards narrower running models. Bowls that were considered narrow 15 years ago are now put in the too wide category. The dilemma for players who have plugged into the really narrow game of late is consistency. Quite simply it's just not possible to make bowls that go very narrow on a green, but still pass on a test table, play consistently on most NZ greens. The new Drakes Pride models now give those players wanting the flatter entry to the head sets that have our robust playing characteristics.

Q. Do I really need more than 1 set?

A. In a word, yes. If you like narrow running bowls you will need an easy-play set for inferior or windy greens. If the only set you have is a wider draw
set, competing against narrower models that play the weighted up-shot well is very difficult as the greens speeds up. It may play brilliantly on a 15-16 sec green but your options are restricted to only draw shots on a 19sec green. The new models are designed to give the same range of shot options as green speed get quicker.

Q. Which model goes best in wind?
A. The Drakes Pride Special, now Ultra has earned the reputation over the past 15 years of being exceptional in moderate and severe wind often experienced in New Zealand. This bowl was built for the southern hemisphere outdoor conditions and is not sold outside Aust/NZ.
The Professional model in its current form was introduced to NZ market in Sept 1998. It is stamped with letters NZ to designate as engineered for New Zealand and has been manufactured for medium speed greens.
This model also is superior in windy conditions, tracks very well on astro-grass and has gained favour very quickly. In general bowls that don't bias-subtract at all or very much handle wind better than those models that go very narrow with a lot of bias-subtraction going on.
The new Delta, Corsair and Direct models are already showing excellent consistency and wind capabilities, the most important aspect of any bowl model.

Q. Should I buy heavy or xtra-heavy weight?
A. Bowls are made from 3 grades/weights of material, medium, heavy & xtra-heavy which are descriptive terms only and do not signify a specific weight. As the various models differ slightly in shape, therefore differ slightly in displacement or weight. Modern slim-style bowls are often slightly lighter in weight than older broad shouldered bowls, adding more arguement towards extra heavy which is only available in black. Coloured bowls available in H only.

Q. Is the weight of an Xtra-heavy size 3 the same as a heavy size 4?
A. No. As a general rule the 3XH bowl is approx 60% of the weight difference between a 3H and 4H.

Q.Why do my bowls track wider than my friends set?

A. While 2 identical sets will take the same bias on a test table, the player's delivery has a great effect on the actual path up the green.

Q. Why do my bowls pull up short as compared with another player's?

A. It is surprising how often we get this comment from bowlers, especially those who have down sized.
It is not possible to make a judgement unless you use both sets, and there is a re-learning process when changing your set,
especially from an older wide drawing model. The weight, size and footprint on the ground all have a bearing.
While there may be a perception that your opponent has a set that gets upto the jack, your set will also if you give them slightly more weight.
Remember no set of bowls will jump out of your hand and go up the green on their own.