Order images in the correct order
Hmm the first few ideas of other things you could look for to make your model a little more sharp...


Examine id's of the images/metadata to see if a statistically significant pattern emerges for how to arrange the images. (i1.png,i2.png,i3.png,etc),(Largest image is always on top, etc)
They may purposely scramble the images in a way were they never let a picture be purposely on the right location which can be used to your advantage. You only have to decide in between three locations the correct location for any image.
You may want to see if you can incorporate word2vec and/or LSTM for getting image to->words to->story syntax/context correct.
If they allow two chances before reseting then your model will be more accurate if you can incorporate that. If it outputs a probability each of the images are at a location then you need to create two guesses not one.


Chances are low but I would be interested to see your results I think if they didn't make a terrible captcha you will have about 16% &lt; x &lt; 30 accuracy if they have systemic flaws could be a lot better.