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Gunfire at Sea: The Challenge of Using Positive Deviants

Positive deviants are people who use an unusual tactic to achieve success.

Key points

  • Positive deviants are the individuals using unusual tactics to achieve success, and we can learn from them.
  • Their tactics may be subtle, and they might not even understand what is working.
  • Expertise is needed to spot positive deviants, diagnose the reasons for their success, and spread the message.

The concept of positive deviance (Sternin & Choo, 2000; Wishik & Van der Vynckt, 1976) is that in any community faced with a problem, there are likely to be some individuals who are successful because they use uncommon strategies, even if they don’t fully understand how those strategies are working. The strategies used by these positive deviants can often be expanded to the benefit of the entire community.

This sounds powerful, and simple. But is it really so simple? Let’s look at a case study — British Navy gunfire at the turn of the 20th century (Morison, 1966).


It wasn’t easy to accurately fire a cannon from a ship back then. Cannon fire wasn’t very accurate even on land. Ships were worse — they rolled with the waves.

Before 1898 what happened was that one sailor, called the gun pointer, estimated the distance to the target, which was usually around 1600 yards. The pointer then turned a small wheel on the gun mount to use the elevating gears to raise the gun barrel so the cannon had the elevation needed to reach the target. Then the gun pointer left the elevation setting in place.

The hardest part was accommodating the roll of the ship. The gun pointer looked through open sights, like you’d find on a rifle, and waited until the roll of the ship brought the sights on the target. At that instant, the gun pointer pressed the firing button to fire the cannon.

Adding to the complication, the gun pointer had to factor in his reaction time from the matching of the target to the pressing of the button, and also factor in the travel of the shell. Therefore, the pointer had to fire a little before the sights lined up with the target, and estimate that lead time.

To summarize, the pointer, on a moving platform, had to estimate the range and shoot while his sight was off the target.

The Breakthrough

Percy Scott was a British Navy captain who commanded the H.M.S. Scylla. Scott, a very colorful and creative individual, lost his patience with how inaccurate the cannon fire was, and stewed about the problem for a few years. The other naval officers at the time seem to have accepted the inaccuracy as what could be expected. Scott wanted to do better.

Scott’s breakthrough came on a rough day in the ocean, during target practice, when the Scylla was pitching and rolling violently. As expected, the gunnery crews were even less accurate than usual because the rolling of the ship was so pronounced. Then Scott noticed that one pointer was much more accurate compared to the others.

Scott watched what this man was doing. Scott discovered that this pointer was unconsciously working his elevating gear back and forth to compensate for the rolling of the ship. Whereas the other pointers left the gun elevation fixed once they set it, this pointer kept fiddling with the elevation in order to have a longer “time on target.” He’d increase the angle as the ship rolled down until it rolled past the aim point Then he would decrease the angle as the ship rolled up. This tactic let the cannon stay pointed at the target for a longer period of time. The tactic gave the gun pointer a larger window for firing. And it made him more accurate.

Scott immediately realized that he could train all of the gun pointers to use this tactic. The gun pointer Scott was watching was working the elevation gear unconsciously — it was just a habit he had picked up. But now that Scott saw how that habit worked, he could teach it so that the other pointers could deliberately use it.

Scott made some other changes.

He changed the gear ratio in the elevating gear. Previously the pointers only used the elevating gear for range, to set the gun in fixed position. Scott made it easier for the gun pointers to elevate and depress the gun so that it could track a target throughout the roll.

This process came to be known as “continuous-aim firing.”

Scott also wanted to improve the training experience so he designed a primitive simulator by rigging a small target at the mouth of the gun. The gunnery team could use a crank to move this target up and down to simulate a moving target. The gun pointer could follow this target as it moved, and fire at it with a subcaliber rifle that was rigged in the breech of the gun. Now the gun pointers were able to practice daily without wasting cannon balls.

Did this approach affect accuracy?

Here are some results. Before using continuous aim firing, in one exercise in 1899, five ships each fired for five minutes at a derelict ship hulk at 1,600 yards. They managed two hits on its sails. Six years later, using continuous-aim firing, one naval gunner made 15 hits in one minute at a target 75 by 25 feet at the same range, 1,600 yards. Even more impressive, half the shots hit a bull’s eye 50 inches square.

Some Lessons

What can we learn from this example?

Scott was frustrated by the inaccurate gunfire — it wasn’t acceptable to him, but the other British Navy officers don’t seem to have been bothered by it.

Scott noticed that one gunnery team was doing much better than the others — he could see that they were consistently achieving better results.

Critically, Scott was able to diagnose the strategy used by the gun pointer on this team even though the man couldn’t articulate what he was doing that was special.

Scott also appreciated that this gun pointer’s strategy could be taught to others.

Finally, Scott devised methods to support the training and execution of the “continuous-aim firing” strategy.

For these reasons, we might want to acknowledge the expertise needed to make positive deviancy pay off.


Morison, E.E. (1966). Men, Machines, and Modern Times, Cambridge, MA: MIT Press.

Sternin, J., & Choo, R. (2000). The power of positive deviancy. Harvard Business Review, 78, 14-15.

SM, Van der Vynckt S. The use of nutritional "positive deviants" to identify approaches for modification of dietary practices. Am J Public Health. 1976;66(1):38-42.

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