Memorizing a Deck of Cards

I just mem­o­rized a deck of cards, be­cause I was told do­ing so would im­prove my fo­cus.

The pro­cess took 2 hours and 13 min­utes, in­clud­ing breaks. I used 20-5 po­modoro at first, and switched to 25-5 in the mid­dle.

I ini­tially wrote a script to simu­late a ran­domly shuffled deck. After mem­o­riz­ing the first 18 cards, I switched to a phys­i­cal deck (putting the same cards on top).

I chose not to use any strat­egy from an out­side source (e.g. mem­ory palace), be­cause I wanted to see what I would come up with on my own, and I thought that us­ing an ex­ter­nal strat­egy might make it too easy.


I be­gan by mem­o­riz­ing cards in groups of four. After mem­o­riz­ing a group, I would go back to the pre­vi­ous group and see if I still knew all of the cards in both groups. Then I would go back an ar­bi­trar­ily far amount (wher­ever I cut the deck), and be­gin from there. Oc­ca­sion­ally, I would go back to the be­gin­ning and go through the deck up to the point I had mem­o­rized to. If I messed up in an ear­lier group, I would re­peat the pro­cess for that group.

How­ever, af­ter three such groups (12 cards), it be­came clear that four was too many to mem­o­rize at once, so I switched to groups of three. I then ran into an­other prob­lem-I could mem­o­rize in­di­vi­d­ual groups fairly eas­ily, but I would have trou­ble re­mem­ber­ing the or­der in which the groups them­selves came. I was able to solve this prob­lem by “link­ing” the groups to­gether—mem­o­riz­ing the last card of the pre­vi­ous group along with the next group.

A few at­tributes of groups made them eas­ier to mem­o­rize:

  • two or more cards in the group share a face or suit

    • for­tu­nately, this is true for most groups

  • the group is mono­ton­i­cally in­creas­ing or decreasing

  • two con­sec­u­tive cards in the group num­bers which are re­lated to one an­other

    • one is a fac­tor of the other (e.g. 3 and 9),

    • they are con­sec­u­tive (e.g. 10 and jack)

The eas­iest group was 4 of spades, 7 of spades, 8 of spades—in­creas­ing and all of the same suit.

Some of my most com­mon mis­takes were:

  • mix­ing up suits of the same color

  • get­ting the or­der of the groups wrong

  • mix­ing up aces and queens

About three hours af­ter my first suc­cess, I went through the deck again, with no prac­tice in be­tween. I only got three of the cards wrong, though I fre­quently had to think for a while.


Some­time into the task, I grew anx­ious that I was wast­ing my time, or that it wouldn’t help, or that I should be work­ing on some­thing else. There were times when I felt an urge to stop and do any­thing else. I of­ten get such urges when do­ing other ac­tivi­ties, but this time I was able to re­sist them. I think that this might be be­cause there was also a clear next step in this task, and also be­cause I knew that the point of the task was to train my fo­cus.


Did this ac­tivity im­prove my fo­cus? I sup­pose we’ll have to wait and see. I was able to write this post, which isn’t some­thing I would nor­mally have the willpower to do, but that may have been me rid­ing on the high of mem­o­riz­ing the deck (It felt so good when I fi­nally mem­o­rized the whole thing). Maybe I’ll post an up­date next week.