How you pick the right thing to change - 70/30 rule

While going to board a flight, this book caught my attention and was a great read for a four hours flight.

What Got You Here Won’t Get You There by Marshall Goldsmith

 In a way, I can see why people have problems choosing what needs fixing. In golf, for example, it is common wisdom that 70 percent of all shots take place within 100 yards of the pin. It’s called the short game, and it involves pitching, chipping, hitting out of sand traps, and putting. If you want to lower your score, focus on fixing your short game; it represents at least 70 percent of your score. Yet if you go to a golf course you’ll see very few people practicing their short game. They’re all at the driving range trying to hit their oversized drivers as far as they can. Statistically, it doesn’t make sense because over the course of 18 holes, they’ll only need their drivers fourteen times (at most) whereas they’ll pull out their short irons and putters at least 50 times. Athletically it doesn’t make sense either. The short game demands compact delicate small-muscle movements; it is much easier to master than the violent big-muscle movements of driving off the tee. Nor does it make sense competitively. 

Actually, the whole book is a great read to improve oneself.