diff --git a/manifest/product_octez.ml b/manifest/product_octez.ml
index 3a97892fc78a014e0d654d897e606035fd3e31b6..c69504fd481608aa622230888f499fb249e0cb8f 100644
--- a/manifest/product_octez.ml
+++ b/manifest/product_octez.ml
@@ -237,7 +237,7 @@ let octez_stdlib =
     ~internal_name:"tezos_stdlib"
     ~path:"src/lib_stdlib"
     ~synopsis:"Yet-another local-extension of the OCaml standard library"
-    ~deps:[hex; zarith; lwt; aches]
+    ~deps:[hex; zarith; lwt; aches; data_encoding]
     ~inline_tests:ppx_expect
     ~foreign_stubs:
       {language = C; flags = []; names = ["tzBytes_c"]; include_dirs = []}
diff --git a/src/lib_protocol_environment/sigs/v16.ml b/src/lib_protocol_environment/sigs/v16.ml
index 31ba26fc7f1c751032feac99e83bf8ba0a5a737d..4f157e0023ad2ac3b61980abe38bb9c6ae256264 100644
--- a/src/lib_protocol_environment/sigs/v16.ml
+++ b/src/lib_protocol_environment/sigs/v16.ml
@@ -5900,6 +5900,12 @@ val fold : ('b -> 'a -> 'b) -> 'a t -> 'b -> 'b
    [fallback] is required to initialize a fresh array before it can be
    filled. *)
 val fold_map : ('b -> 'a -> 'b * 'c) -> 'a t -> 'b -> 'c -> 'b * 'c t
+
+(** [encoding ?max_length e] is a data encoding for fallback arrays
+    whose elements are encoded with [e]. If [max_length] is provided,
+    the length of the encoded arrays is bounded by [max_length]. *)
+val encoding :
+  ?max_length:int -> 'a Data_encoding.encoding -> 'a t Data_encoding.encoding
 end
 # 48 "v16.in.ml"
 
diff --git a/src/lib_protocol_environment/sigs/v16/fallbackArray.mli b/src/lib_protocol_environment/sigs/v16/fallbackArray.mli
index 604bec65029e62cfbccf0d3ce91f28e8e7097a2a..5b57b61f1c50ff4e4a52da541b6384e459142828 100644
--- a/src/lib_protocol_environment/sigs/v16/fallbackArray.mli
+++ b/src/lib_protocol_environment/sigs/v16/fallbackArray.mli
@@ -82,3 +82,9 @@ val fold : ('b -> 'a -> 'b) -> 'a t -> 'b -> 'b
    [fallback] is required to initialize a fresh array before it can be
    filled. *)
 val fold_map : ('b -> 'a -> 'b * 'c) -> 'a t -> 'b -> 'c -> 'b * 'c t
+
+(** [encoding ?max_length e] is a data encoding for fallback arrays
+    whose elements are encoded with [e]. If [max_length] is provided,
+    the length of the encoded arrays is bounded by [max_length]. *)
+val encoding :
+  ?max_length:int -> 'a Data_encoding.encoding -> 'a t Data_encoding.encoding
diff --git a/src/lib_stdlib/dune b/src/lib_stdlib/dune
index 6266e6e4743b303298172150abab3ccbdf58e03f..ac2c3b77c9b4136c53798483c0d18c93f8ff39e5 100644
--- a/src/lib_stdlib/dune
+++ b/src/lib_stdlib/dune
@@ -9,7 +9,8 @@
   hex
   zarith
   lwt
-  aches)
+  aches
+  octez-libs.data-encoding)
  (inline_tests (flags -verbose) (modes native))
  (preprocess (pps ppx_expect))
  (foreign_stubs (language c) (names tzBytes_c)))
diff --git a/src/lib_stdlib/fallbackArray.mli b/src/lib_stdlib/fallbackArray.mli
index 604bec65029e62cfbccf0d3ce91f28e8e7097a2a..5b57b61f1c50ff4e4a52da541b6384e459142828 100644
--- a/src/lib_stdlib/fallbackArray.mli
+++ b/src/lib_stdlib/fallbackArray.mli
@@ -82,3 +82,9 @@ val fold : ('b -> 'a -> 'b) -> 'a t -> 'b -> 'b
    [fallback] is required to initialize a fresh array before it can be
    filled. *)
 val fold_map : ('b -> 'a -> 'b * 'c) -> 'a t -> 'b -> 'c -> 'b * 'c t
+
+(** [encoding ?max_length e] is a data encoding for fallback arrays
+    whose elements are encoded with [e]. If [max_length] is provided,
+    the length of the encoded arrays is bounded by [max_length]. *)
+val encoding :
+  ?max_length:int -> 'a Data_encoding.encoding -> 'a t Data_encoding.encoding
diff --git a/src/lib_stdlib/readOnlyArray.ml b/src/lib_stdlib/readOnlyArray.ml
index df2724b5018ddd48c3b45cec04aea97c0e211741..74e83c6fef8fd8bbd69bfdb9435bbb463e2fc788 100644
--- a/src/lib_stdlib/readOnlyArray.ml
+++ b/src/lib_stdlib/readOnlyArray.ml
@@ -102,3 +102,5 @@ let fold_map f array init fallback =
       aux accu (idx + 1)
   in
   (aux init 0, output)
+
+let encoding = Data_encoding.array
diff --git a/src/proto_alpha/lib_parameters/default_parameters.ml b/src/proto_alpha/lib_parameters/default_parameters.ml
index 042c0b44438776abf8841081c847b77909fb5403..611b67188b17225792c7d519e87a7618369b89f1 100644
--- a/src/proto_alpha/lib_parameters/default_parameters.ml
+++ b/src/proto_alpha/lib_parameters/default_parameters.ml
@@ -388,6 +388,8 @@ let constants_mainnet : Constants.Parametric.t =
     cache_stake_distribution_cycles = 5;
     (* One for the sampler state for all cycles stored at any moment (as above). *)
     cache_sampler_state_cycles = 5;
+    (* One for the SWRR selected distribution for all cycles stored at any moment (as above). *)
+    cache_swrr_selected_distribution_cycles = 5;
     dal = default_dal;
     sc_rollup;
     zk_rollup =
diff --git a/src/proto_alpha/lib_plugin/RPC.ml b/src/proto_alpha/lib_plugin/RPC.ml
index 289b1d08919f1fd82cd6f9269823e4daf486c74e..67f31d05850cf5704666b335f2283d9cabb97382 100644
--- a/src/proto_alpha/lib_plugin/RPC.ml
+++ b/src/proto_alpha/lib_plugin/RPC.ml
@@ -4452,7 +4452,13 @@ let register () =
         |> Cycle.to_int32 |> Cycle_repr.of_int32_exn
       in
       let ctxt = Alpha_context.Internal_for_tests.to_raw ctxt in
-      Storage.Stake.Selected_bakers.find ctxt cycle) ;
+      let* baker_array = Storage.Stake.Selected_bakers.find ctxt cycle in
+      match baker_array with
+      | None -> return_none
+      | Some baker_array ->
+          return_some
+            FallbackArray.(
+              Stdlib.List.init (length baker_array) (get baker_array))) ;
   Registration.register0 ~chunked:false S.swrr_credits (fun ctxt () () ->
       let ctxt = Alpha_context.Internal_for_tests.to_raw ctxt in
       Stake_storage.fold_on_active_delegates_with_minimal_stake_es
diff --git a/src/proto_alpha/lib_protocol/alpha_context.mli b/src/proto_alpha/lib_protocol/alpha_context.mli
index a72e6da59fd190a4d184f158ec7b2bd7b6eec2d3..41597dab5ad2b23630c5c61483db47b0971d56a3 100644
--- a/src/proto_alpha/lib_protocol/alpha_context.mli
+++ b/src/proto_alpha/lib_protocol/alpha_context.mli
@@ -980,6 +980,7 @@ module Constants : sig
       cache_script_size : int;
       cache_stake_distribution_cycles : int;
       cache_sampler_state_cycles : int;
+      cache_swrr_selected_distribution_cycles : int;
       dal : dal;
       sc_rollup : sc_rollup;
       zk_rollup : zk_rollup;
diff --git a/src/proto_alpha/lib_protocol/constants_parametric_repr.ml b/src/proto_alpha/lib_protocol/constants_parametric_repr.ml
index 73d79d97910b28b1a79e4d597faa56e02be1e3cc..4384787aa2d0ff2f3f0344a541d0920ac6bb66c4 100644
--- a/src/proto_alpha/lib_protocol/constants_parametric_repr.ml
+++ b/src/proto_alpha/lib_protocol/constants_parametric_repr.ml
@@ -325,6 +325,7 @@ type t = {
   cache_script_size : int;
   cache_stake_distribution_cycles : int;
   cache_sampler_state_cycles : int;
+  cache_swrr_selected_distribution_cycles : int;
   dal : dal;
   sc_rollup : sc_rollup;
   zk_rollup : zk_rollup;
@@ -632,7 +633,8 @@ let encoding =
                 c.initial_seed ),
               ( ( c.cache_script_size,
                   c.cache_stake_distribution_cycles,
-                  c.cache_sampler_state_cycles ),
+                  c.cache_sampler_state_cycles,
+                  c.cache_swrr_selected_distribution_cycles ),
                 ( c.dal,
                   ( (c.sc_rollup, c.zk_rollup),
                     ( c.adaptive_issuance,
@@ -679,7 +681,8 @@ let encoding =
                    initial_seed ),
                  ( ( cache_script_size,
                      cache_stake_distribution_cycles,
-                     cache_sampler_state_cycles ),
+                     cache_sampler_state_cycles,
+                     cache_swrr_selected_distribution_cycles ),
                    ( dal,
                      ( (sc_rollup, zk_rollup),
                        ( adaptive_issuance,
@@ -729,6 +732,7 @@ let encoding =
         cache_script_size;
         cache_stake_distribution_cycles;
         cache_sampler_state_cycles;
+        cache_swrr_selected_distribution_cycles;
         dal;
         sc_rollup;
         zk_rollup;
@@ -792,10 +796,11 @@ let encoding =
                    (opt "testnet_dictator" Signature.Public_key_hash.encoding)
                    (opt "initial_seed" State_hash.encoding))
                 (merge_objs
-                   (obj3
+                   (obj4
                       (req "cache_script_size" int31)
                       (req "cache_stake_distribution_cycles" int8)
-                      (req "cache_sampler_state_cycles" int8))
+                      (req "cache_sampler_state_cycles" int8)
+                      (req "cache_swrr_selected_distribution_cycles" int8))
                    (merge_objs
                       (obj1 (req "dal_parametric" dal_encoding))
                       (merge_objs
diff --git a/src/proto_alpha/lib_protocol/constants_parametric_repr.mli b/src/proto_alpha/lib_protocol/constants_parametric_repr.mli
index 2d44cffef908d2288b4cb3f2a9bdee9cda0202fc..e9bdc676020c69d93450d495baa5e82c017a27f0 100644
--- a/src/proto_alpha/lib_protocol/constants_parametric_repr.mli
+++ b/src/proto_alpha/lib_protocol/constants_parametric_repr.mli
@@ -262,6 +262,8 @@ type t = {
   (* in cycles *)
   cache_sampler_state_cycles : int;
   (* in cycles *)
+  cache_swrr_selected_distribution_cycles : int;
+  (* in cycles *)
   dal : dal;
   sc_rollup : sc_rollup;
   zk_rollup : zk_rollup;
diff --git a/src/proto_alpha/lib_protocol/constants_repr.ml b/src/proto_alpha/lib_protocol/constants_repr.ml
index cdddf4f53e39642adf07cdfaa1e38f1692bdf8f0..390b539eedc9d522339cd419fb70e4658682f8e3 100644
--- a/src/proto_alpha/lib_protocol/constants_repr.ml
+++ b/src/proto_alpha/lib_protocol/constants_repr.ml
@@ -64,7 +64,7 @@ let michelson_maximum_type_size = 2001
 
 (* This constant declares the number of subcaches used by the cache
    mechanism (see {Context.Cache}). *)
-let cache_layout_size = 3
+let cache_layout_size = 4
 
 (* /!\ Several parts of the codebase may assume that
    [denunciation_period = 1] and [slashing_delay = 1] **without being
@@ -608,4 +608,5 @@ let cache_layout p =
       p.cache_script_size;
       p.cache_stake_distribution_cycles;
       p.cache_sampler_state_cycles;
+      p.cache_swrr_selected_distribution_cycles;
     ]
diff --git a/src/proto_alpha/lib_protocol/delegate_sampler.ml b/src/proto_alpha/lib_protocol/delegate_sampler.ml
index d5c42f1f57d2916ed71984e740664688c426337f..94309190ccd5ee6cb1a4a2b9634b053d2afd09b9 100644
--- a/src/proto_alpha/lib_protocol/delegate_sampler.ml
+++ b/src/proto_alpha/lib_protocol/delegate_sampler.ml
@@ -345,7 +345,7 @@ let clear_outdated_sampling_data ctxt ~new_cycle =
   | Some outdated_cycle ->
       let* ctxt = Delegate_sampler_state.remove ctxt outdated_cycle in
       let* ctxt = Seed_storage.remove_for_cycle ctxt outdated_cycle in
-      let*! ctxt = Swrr_sampler.remove_outdated_cycle ctxt outdated_cycle in
+      let* ctxt = Swrr_sampler.remove_outdated_cycle ctxt outdated_cycle in
       return ctxt
 
 let attesting_power ~all_bakers_attest_enabled ctxt level =
diff --git a/src/proto_alpha/lib_protocol/raw_context.ml b/src/proto_alpha/lib_protocol/raw_context.ml
index a567971a705941a7486995ec72a0ca643c579443..f754260d80647a300f02f8c45e39529a2e0a3e0c 100644
--- a/src/proto_alpha/lib_protocol/raw_context.ml
+++ b/src/proto_alpha/lib_protocol/raw_context.ml
@@ -1269,6 +1269,7 @@ let prepare_first_block ~level ~timestamp chain_id ctxt =
                  cache_script_size;
                  cache_stake_distribution_cycles;
                  cache_sampler_state_cycles;
+                 cache_swrr_selected_distribution_cycles;
                  dal = _;
                  sc_rollup = _;
                  zk_rollup = _;
@@ -1323,6 +1324,7 @@ let prepare_first_block ~level ~timestamp chain_id ctxt =
             cache_script_size;
             cache_stake_distribution_cycles;
             cache_sampler_state_cycles;
+            cache_swrr_selected_distribution_cycles;
             dal;
             sc_rollup;
             zk_rollup;
@@ -1622,6 +1624,7 @@ let prepare_first_block ~level ~timestamp chain_id ctxt =
             cache_script_size;
             cache_stake_distribution_cycles;
             cache_sampler_state_cycles;
+            cache_swrr_selected_distribution_cycles = cache_sampler_state_cycles;
             dal;
             sc_rollup;
             zk_rollup;
diff --git a/src/proto_alpha/lib_protocol/storage.ml b/src/proto_alpha/lib_protocol/storage.ml
index 39345190f47a8bf34e67b8d169357910cd473308..6c94f333772ad758167bb9aba66d242bf9a0d11c 100644
--- a/src/proto_alpha/lib_protocol/storage.ml
+++ b/src/proto_alpha/lib_protocol/storage.ml
@@ -1330,10 +1330,9 @@ module Cycle = struct
         let name = ["selected_bakers"]
       end)
       (struct
-        type t = Signature.Public_key_hash.t list
+        type t = Signature.Public_key_hash.t FallbackArray.t
 
-        let encoding =
-          Data_encoding.(Variable.list Signature.Public_key_hash.encoding)
+        let encoding = FallbackArray.encoding Signature.Public_key_hash.encoding
       end)
 
   module Total_active_stake =
diff --git a/src/proto_alpha/lib_protocol/storage.mli b/src/proto_alpha/lib_protocol/storage.mli
index ec2958e7330634b572d0036f2abf22e0f3a37cce..00e1b8a608ab319f9561b4def0504cfbbc911318 100644
--- a/src/proto_alpha/lib_protocol/storage.mli
+++ b/src/proto_alpha/lib_protocol/storage.mli
@@ -620,7 +620,7 @@ module Stake : sig
   module Selected_bakers :
     Indexed_data_storage
       with type key = Cycle_repr.t
-       and type value = Signature.Public_key_hash.t list
+       and type value = Signature.Public_key_hash.t FallbackArray.t
        and type t := Raw_context.t
 
   (** Sum of the active stakes of all the delegates with
diff --git a/src/proto_alpha/lib_protocol/swrr_sampler.ml b/src/proto_alpha/lib_protocol/swrr_sampler.ml
index 20cad7b9330206b3701e089d6dfae0ab1d1bca61..470af2aecbe736169bd1f159f4b0d046441f2baf 100644
--- a/src/proto_alpha/lib_protocol/swrr_sampler.ml
+++ b/src/proto_alpha/lib_protocol/swrr_sampler.ml
@@ -7,6 +7,54 @@
 
 type credit_info = {pkh : Signature.public_key_hash; credit : Z.t; stake : Z.t}
 
+module Swrr_selected_distribution = struct
+  module Cache_client = struct
+    type cached_value = Signature.Public_key_hash.t FallbackArray.t
+
+    let namespace = Cache_repr.create_namespace "swrr_selected_distribution"
+
+    let cache_index = 3
+
+    let value_of_identifier ctxt identifier =
+      let cycle = Cycle_repr.of_string_exn identifier in
+      Storage.Stake.Selected_bakers.get ctxt cycle
+  end
+
+  module Cache = (val Cache_repr.register_exn (module Cache_client))
+
+  let identifier_of_cycle cycle = Format.asprintf "%a" Cycle_repr.pp cycle
+
+  (* that's symbolic: 1 cycle = 1 entry *)
+  let size = 1
+
+  let init ctxt cycle delegates =
+    let open Lwt_result_syntax in
+    let id = identifier_of_cycle cycle in
+    let* ctxt = Storage.Stake.Selected_bakers.init ctxt cycle delegates in
+    let*? ctxt = Cache.update ctxt id (Some (delegates, size)) in
+    return ctxt
+
+  let find ctxt cycle =
+    let open Lwt_result_syntax in
+    let id = identifier_of_cycle cycle in
+    let* ctxt, cached_opt = Cache.find ctxt id in
+    match cached_opt with
+    | Some _ as some_cache -> return (ctxt, some_cache)
+    | None ->
+        let* delegates = Storage.Stake.Selected_bakers.find ctxt cycle in
+        let*? ctxt =
+          Cache.update ctxt id (Option.map (fun v -> (v, size)) delegates)
+        in
+        return (ctxt, delegates)
+
+  let remove ctxt cycle =
+    let open Lwt_result_syntax in
+    let id = identifier_of_cycle cycle in
+    let*? ctxt = Cache.update ctxt id None in
+    let*! ctxt = Storage.Stake.Selected_bakers.remove ctxt cycle in
+    return ctxt
+end
+
 let select_bakers_at_cycle_end ctxt ~target_cycle =
   let open Lwt_result_syntax in
   let* total_stake = Stake_storage.get_total_active_stake ctxt target_cycle in
@@ -75,8 +123,14 @@ let select_bakers_at_cycle_end ctxt ~target_cycle =
   in
   let new_credits, selected_bakers = loop 0 init_credit_list [] in
   (* update context *)
-  let*! ctxt =
-    Storage.Stake.Selected_bakers.add ctxt target_cycle selected_bakers
+  let* ctxt =
+    Swrr_selected_distribution.init
+      ctxt
+      target_cycle
+      (FallbackArray.of_list
+         ~fallback:Signature.Public_key_hash.zero
+         ~proj:(fun pkh -> pkh)
+         selected_bakers)
   in
   let*! ctxt =
     List.fold_left_s
@@ -95,21 +149,15 @@ let get_baker ctxt level round =
   let cycle = level.Level_repr.cycle in
   let pos = level.Level_repr.cycle_position in
   let*? round_int = Round_repr.to_int round in
-
-  let* selected_bakers = Storage.Stake.Selected_bakers.find ctxt cycle in
+  let* ctxt, selected_bakers = Swrr_selected_distribution.find ctxt cycle in
   match selected_bakers with
   | None -> return (ctxt, None)
-  | Some selected_bakers -> (
-      let len = List.length selected_bakers in
+  | Some selected_bakers ->
+      let len = FallbackArray.length selected_bakers in
       let idx = (Int32.to_int pos + (3 * round_int)) mod len in
-
-      match List.nth_opt selected_bakers idx with
-      | None ->
-          assert false
-          (* should not happen if select_bakers_at_cycle_end is correct *)
-      | Some pkh ->
-          let* pk = Delegate_consensus_key.active_pubkey ctxt pkh in
-          return (ctxt, Some pk))
+      let pkh = FallbackArray.get selected_bakers idx in
+      let* pk = Delegate_consensus_key.active_pubkey ctxt pkh in
+      return (ctxt, Some pk)
 
 let reset_credit_for_deactivated_delegates ctxt deactivated_delegates =
   let open Lwt_result_syntax in
@@ -125,4 +173,4 @@ let reset_credit_for_deactivated_delegates ctxt deactivated_delegates =
   in
   return ctxt
 
-let remove_outdated_cycle = Storage.Stake.Selected_bakers.remove
+let remove_outdated_cycle = Swrr_selected_distribution.remove
diff --git a/src/proto_alpha/lib_protocol/swrr_sampler.mli b/src/proto_alpha/lib_protocol/swrr_sampler.mli
index 1ef3bb332b5f57658098830764996eba0e51e07d..d3ef428dc30fe144e364633728130f546436ef16 100644
--- a/src/proto_alpha/lib_protocol/swrr_sampler.mli
+++ b/src/proto_alpha/lib_protocol/swrr_sampler.mli
@@ -22,4 +22,5 @@ val reset_credit_for_deactivated_delegates :
   Signature.Public_key_hash.t list ->
   Raw_context.t tzresult Lwt.t
 
-val remove_outdated_cycle : Raw_context.t -> Cycle_repr.t -> Raw_context.t Lwt.t
+val remove_outdated_cycle :
+  Raw_context.t -> Cycle_repr.t -> Raw_context.t tzresult Lwt.t