To use or not to use. Shield.

Every time i go out of the game, i use shield. I know that in case of attack of stronger player I would lose about 20 trophies. And now very difficult for me to win these trophies back. But from the other side if weaker player would attack me, and i win, i can gain some trophies. So, I want someone who dont use shield please, tell us about your expirience. May be this shield is only waste of crystals? I want to know your opinion.

okay, i never use shields.. The reason is very simple I know for a fact that its quite impossible for me to lose while losing more than 3 - 6 trophies..

Background on how trophies are won or lost: The trophies gain or loss depends on the difference of rating and how badly you were beaten.
While attacking if the stats show that you can gain 25 trophies winning and lose 25 trophies losing, this means that if you lose the battle you will immediately lose 25 trophies but if u win it depends on how well you win (to win you have to atleast reduce 50% of the opponents troops). If you defeat 50 - 74% of the troops you get 1/3rd of the trophies rounded up (9 trophies in this example) if you defeat 75 - 99% of the troops you get 2/3rd of the trophies rounded up (17 trophies) and if you defeat 100% you gain all 25 trophies!!

While defending it works the same way but in your advantage. You will always win or lose the number of trophies the other person loses or wins. for example if the person in the previous example defeats 79% of your troops then you will lose 17 trophies and he will gain 17 trophies. on the other hand if he manages to defeat only 49% of your troops you will instantly be awarded 25 trophies and he will lose the same amount!

So if a player who is much stronger than you attacks you he is bound to have a much higher rating in which case he can at-most get 1 to 3 trophies (because he will defeat me completely - 100%).. on the other hand people who are my same rating or near my rating are generally not able to defeat me by more than 75% which means i will lose at-most 6-9 trophies. The number of trophies lost are quite insignificant compared to the price of the shield. The fact that I will not be able to let the shield run its full duration (1 day) is all the more reason for me to never use it (1 day = 24hrs = 48 energy.. maximum energy is can store is 20 )

So my advice in general would be never to use a shield unless u are trying to get enough resources to build or upgrade something (eg: 5000000 mojo for final barrack upgrade).

One exception to what i have said above is the case where you have really high trophy count and you have people with the same trophy count who are much stronger than you .. this is especially the case when you have a looot of trophies (4000+).. in this case you might want to protect your trophy count by using a shield, but always take into consideration that winning while defending will generally give you a lot of trophies as well

Sorry for the wall of text .. hope it is quite clear, please let me know if something is not clear.

using shield make seance if you collect resources for 9-10 lvl of town hall, barrack or arsenal, collecting mojo on Sagittarius/Capricorn. you cant play more then 2 days( it mean that you may lose 4 or more times). for every day using doesn't make seance, especially after removing 12h shield
BUT you decide, its your crystals. my choice is using crystals for faster upgrade

I'd personally advocate against the use of shield, unless you really care that much about losing trophies.

Now as some of you have already mentioned there is also the possibility that someone weaker than you will attack you and thus give you crystals. This was actually how I raised my trophy count from 3300 to 3700. I get nothing from attacking, so this was the only way I had to grow.
However, that being said, my main reason for not buying a shield is the following; whenever someone defeats you, a shield of 12 hours is being added to your account. This means I have 12 hours until I can be attacked again. Considering that I know for a fact that I will be able to have my phone just idling in the game for several hours a day, this seems like a decent deal to me. Furthermore I also make it a point to spend as much mojo and gold as possible before logging off for more than 30 minutes. To further strenghten this tactic I always try to do as many attacks as possible per session that I am online, which means that I don't have to break an active shield to finish all my attacks.