This is my tab of Your Biggest Mistake, A just an acoustic guitar version, its 
with a capo on the 5th fret,its pretty accurate so enjoy!! :)

Intro/verse part 1

Am                    C                      G
|--------1----------------------0-------------------3---------------|
|-----------2-----------------------1------------------3------------|
|----2----------2----------0-------------0------0---------0---------|
|--2---2--2---2---------2-----2---2----2----------------------------|
|--0---0--0---0---------3-----3---3----3------2---2---2--2----------|
|---------------------------------------------3---3---3--3----------|

Am
|-------1--------------------|
|---------2------------------|
|----2--------2--------------|
|--2--2--2--2----------------|
|--0--0--0--0----------------|
|----------------------------|


Verse Part 2


   F        G 
But you let go
         Am      G
Cos your hope is gone
      F                  G
And every question fades away


Pre Chorus.

      C                             G
Its a shame you dont know what your running from
           Am                         G
Would your bones have to break an your lights turn off
         F              G                  C             G        Am
would it take the end of time to hear your hearts false start. . . 


Chorus

    G                             Am
You know this is your biggest mistake
             G                         C
what a waste what a waste what a waste
       G                             Am
And of all the things you never explained
    G
You know this is your biggest mistake


Intro/verse part 1 repeated


bridge

C                  G
Wipe the mud spray from your face
Am               G
stop the engine, Stop pretendin
C                  G
Wipe the mud spray from your face 
Am               G
stop the engine, stop pretendin
F
That your still breathing. . . 


Then its just the pre chorus an chorus again and your done!! :) 

Ending the song on an Am sounds the best :)

Hope you enjoy it!!