Why do slumps start

[BowlingTechGirl]

Why do slumps and mental fatigue start.They usually start because of the daily rigors of the same practice and training routines,they can make you feel demotivated,which can promote a slump.The benefits of changing up your routine helps to create new motivation and productivity.
Research shows that the motivation and productivity of workers increases when their work environment is altered.Similarly with bowlers and other athletes that complain of becoming stale,they take time off for a while to do something completely different,and then return all recharged.
The same principal applies to your individual training and practice sessions.If the same routines is getting old and getting you down,or you feel demotivated,try a change of pace in workouts and a change of scenery,and a different center to practice at.
Bowlers to often become obsessive,to the point of addiction in their routines,they are pursuing quantity over any quality because they are afraid that one missed session will totally damage their program.When in fact,their training has become to stressful and predictable can do more damage than just missing one day.A general rule,over training can do more harm to your mental state and performance than under training.

[Mudpuppy]

I think there is a lot to what you say - slumps start and continue to exist when you refuse to change anything.

[Mike White]

Bowlers to often become obsessive,to the point of addiction in their routines,they are pursuing quantity over any quality because they are afraid that one missed session will totally damage their program.

Aslan, she's talking about you.

[Hampe]

Aslan, she's talking about you.Lol.....and here I was thinking of a subtle way to point that out....

[vdubtx]

Lol.....and here I was thinking of a subtle way to point that out....

Subtlety does not work with Aslan.

I do agree with OP, slumps can begin when you are in a comfort zone with no changes in place with your routine.

[swingset]

Slumps, in my experience, also are a product of a slow erosion of your mechanics. And, because it's slow, you don't always notice bad habits creeping in...especially with timing and footwork.

[RobLV1]

Slumps can also be caused by incorporating a change into your game, and falling into the "some is good, but more is better" trap where the change is overdone and becomes a detriment rather than a help.