The Tizzy Angle

Spitfire intercepting a Lancaster bomber

What is the cost of perfection?

Somewhere in the skies over the English Channel a wing of bombers sped toward England, and the best minds in the Royal Air Force had no idea how to stop them. On this afternoon in 1936, those bombers bore the Union Jack, and this was just a training exercise, but Wing Commander Eustace Grenfell and everyone watching from Biggin Hill Sector Station knew it was only a matter of time before those incoming planes would be German.  And it would mean the lives of their countrymen if their pilots couldn’t intercept those bombers before they reached their targets. On this day, despite endless trials over the previous months, Grenfell’s pilots were once again left maneuvering to the radio chatter of scientists barking coordinates that led to nothing but empty blue sky.

The exercise had lasted all day and Grenfell’s fighters had not even come close. Scientists on his staff had worked on ever more complicated calculations to allow them to direct fighters precisely to their targets’ location and continued to fail. His team of scientific advisors were worn out.  Tempers flared.  Listening to the team argue over the interception calculations was too much. Despite all the bright minds and advanced degrees, his team had not managed to successfully intercept one aircraft. Planes of that era were flying more than 200 mph, and by the time Biggin Hill sent pilots courses to fly, the targets were long gone from that location. The RAF had designed the Dowding System, a state-of-the-art network of radar stations, to give early warning of incoming attacks, but unless they could figure out how to turn that radar information into usable instructions for their fighters the system was expensive junk. Translating data into action was simply too slow.

Grenfell was exasperated.  The flurry of calculations, the arguments, the failure; they drove him crazy. In frustration he bellowed at the scientists that he could guide the intercept better. Faster.  Without all the math.  Incredulous, they called his bluff, thinking the career military man didn’t understand the difficult calculations required to guide the fighters to the bombers.  Grenfell examined the raid markers on the Sector Operations table and began radioing vectors to the fighters.

“Steer seventy degrees,” he ordered.

Diagram of the steps required to calculate the tizzy angle

Calculating the Tizzy Angle was a simple 4-step process

Everyone was silent.  The fighters neared the bombers.  The bombers changed their course.  Grenfell paused a few seconds and radioed a new vector.  He was eyeballing it, but the fighters drew closer.  Grenfell continued to adjust the fighters course, refining it until they were behind the bombers.  The fighters radioed that the bombers were in sight.  The intercept was successful. The scientists could not believe it,.  It was beginner’s luck.  So Grenfell did it again, repeating his success.  A 93 percent success rate confirmed his technique.  He had succeeded where the best minds had failed.  And his answer was to shoot from the hip. Grenfell wasn’t interested in finding the perfect intercept calculation. All that concerned him was the practical goal of getting his fighters to their targets.

Sir Henry Tizard, the chief scientist on the Dowding System examined Grenfell’s process. He quickly realized that Grenfell had stumbled upon the Principle of Equal Angles. In essence, Grenfell realized the key to compensating for the extraordinary speed of modern aircraft was to make a rough estimate of where the targets would be, not where they were, similar to the way a shooter must aim ahead of a moving target to hit it.

The procedure was simple. The Controller created the base of the isosceles triangle by drawing a line through the fighters to the bombers.

He created the next leg by drawing a line from the “enemy” bombers to their projected target. The angle between the legs was the critical angle.  The Controller drew a final line, from the fighters using the same critical angle. This leg was the same length as the line from the bombers to their target.  Where these two lines met was the intercept point.  Because the fighters flew faster than the bombers, they would arrive there first. If they did not sight the bombers on arrival, the fighters circled until the bombers arrived. This system wasn’t perfect or precise, but it was fast and it worked.

If this sounds complex, look at the image.  The procedure was simple enough that the Controller could do it by eye.  If the bombers changed course, he redrew the triangle.

Tizard recognized that this was the missing solution.  He threw out the tables and pages of calculations.  In a cruel twist of fate, the process became known not as the Grenfell Angle, but as the Tizzy Angle. Regardless, the RAF published an illustrated guide and dispersed the instructions to all Sectors. This quick rule of thumb calculation improved interception rates when real German bombers sped across the English Channel toward British targets. The Tizzy Angle allowed the RAF to meet and challenge the enemy, saving countless lives. Improvisation proved more useful than precise calculation.

Action This Day

So what are our teams doing?  Are we perfecting our calculations, forever a few minutes too late? Or are we taking action and recalculating as necessary?

Are we obsessing over perfecting deliverables?  Are we spending time reviewing documentation, catching the typos, rewriting phrases?  Are we struggling with the order of the bullet points in your next briefing?

It’s human nature.  We want control. We want to avoid blame for mistakes.  So we over-edit, over-think, over-plan. We pursue perfection.  And just like with the interception problem, this becomes crippling.  Grenfell had an outsider’s perspective.  He was able to view the problem differently.  Here’s what he knew:

The goal is not perfection

Grenfell understood that the goal was to intercept the enemy, not solve a calculation.  The scientists lost sight of that.  You and your team also have a goal and I am fairly sure it’s not “to write a perfect test plan” or “to draft a typo-free training report.”  It is to solve a problem.  The people you answer to want intercepted planes. They do not want you pointing at pages of calculations while standing in a pile of rubble.

Perfection is not possible

Grenfell realized perfect calculations were impossible.  Too many variables changing too rapidly.  Does that sound like your situation at work?  Its time to realize, like Grenfell, that perfection is not possible in any environment.

You will exhaust your team

Is your team apathetic? Are they making too many mistakes? Are they frustrated?  They are probably like the scientists in the intercept problem. Frustrated at their lack of success.

If you want to accomplish goals, apply the lessons of Wing Commander Grenfell and the Tizzy Angle. Take decisive action, make a best effort, build a minimum viable product.  Empower your team to do the same thing, and don’t sweat the small things. Mistakes will happen; errors will be made.  When they do, pivot and readjust, like the recalculations made with the Tizzy Angle.

 Let’s talk about this.  When have your teams suffered in the pursuit of perfection?  Where do you draw the line? How can you distinguish between ensuring quality and becoming obsessed with perfection?

  • Matt Cross

    Great post! I recently worked with a team that was so obsessed with perfection that they missed the fact that they weren’t getting much done. I felt like I was the only one who understood the dilemma. Thankfully I worked closely with a great executive who understood how to move the ball forward. That is when I realized that Great leaders know that perfection is the enemy of progress. Often it is better to use a less than perfect solution to get a better than nothing result!