diff --git a/src/fd_client.erl b/src/fd_client.erl
index cd93919..efb6fc2 100644
--- a/src/fd_client.erl
+++ b/src/fd_client.erl
@@ -312,7 +312,7 @@ ws_tetris2(Sock, Request, Received) ->
     case fd_ws:handshake(Request) of
         {ok, Response} ->
             respond(Sock, Response),
-            tetris_init(Sock),
+            {ok, _} = fd_tetris:start_link(),
             ws_tetris_loop(Sock, [], Received);
         Error ->
             tell("ws_tetris: error: ~tp", [Error]),
@@ -334,11 +334,11 @@ ws_tetris_loop(Sock, Frames, Received) ->
             receive
                 {tcp, Sock, Bin} ->
                     Rcv1 = <<Received/binary, Bin/binary>>,
-                    tell("~p:~p rcv1: ~tp", [?MODULE, ?LINE, Rcv1]),
+                    ok = tell("~p:~p rcv1: ~tp", [?MODULE, ?LINE, Rcv1]),
                     ws_tetris_loop(Sock, Frames, <<>>);
-                {tetris, State} ->
-                    tell("tetris: ~p", [State]),
-                    fd_ws:send(Sock, {text, State}),
+                {tetris, Message} ->
+                    ok = tell("tetris: ~p", [Message]),
+                    ok = fd_ws:send(Sock, {text, Message}),
                     ws_tetris_loop(Sock, Frames, Received);
                 {tcp_closed, Sock}        -> {error, tcp_closed};
                 {tcp_error, Sock, Reason} -> {error, {tcp_error, Reason}}
@@ -349,18 +349,6 @@ ws_tetris_loop(Sock, Frames, Received) ->
             {error, {inet, Reason}}
     end.
 
-tetris_init(_Sock) ->
-    tell("~p tetris_init", [self()]),
-    Parent = self(),
-    _Child = spawn_link(fun() -> poop(Parent) end),
-    ok.
-
-poop(Parent) ->
-    tell("~p poop(~p)", [self(), Parent]),
-    Parent ! {tetris, "poop\n"},
-    timer:sleep(3_000),
-    poop(Parent).
-
 %% ------------------------------
 %% echo
 %% ------------------------------
@@ -390,7 +378,7 @@ ws_echo_loop(Sock) ->
 ws_echo_loop(Sock, Frames, Received) ->
     tell("~p ws_echo_loop(Sock, ~tp, ~tp)", [self(), Frames, Received]),
     case fd_ws:recv(Sock, Received, 5*fd_ws:min(), Frames) of
-        Result = {ok, Message, NewFrames, NewReceived} ->
+        {ok, Message, NewFrames, NewReceived} ->
             tell("~p echo message: ~tp", [self(), Message]),
             % send the same message back
             ok = fd_ws:send(Sock, Message),
diff --git a/src/fd_sfc.erl b/src/fd_sfc.erl
index 04a76d0..c273451 100644
--- a/src/fd_sfc.erl
+++ b/src/fd_sfc.erl
@@ -62,7 +62,7 @@ start_link() ->
 %% gen_server callbacks
 
 init(none) ->
-    log(info, "starting fd_cache"),
+    tell("starting fd_sfc"),
     InitState = #s{},
     erlang:send_after(InitState#s.auto_renew, self(), auto_renew),
     {ok, InitState}.
diff --git a/src/fd_tetris.erl b/src/fd_tetris.erl
new file mode 100644
index 0000000..a00aa42
--- /dev/null
+++ b/src/fd_tetris.erl
@@ -0,0 +1,76 @@
+% @doc tetris
+%
+% manages state for a single game of tetris
+%
+% https://www.erlang.org/docs/24/man/gen_server
+-module(fd_tetris).
+
+-behavior(gen_server).
+
+-export([
+    %% caller context
+    start_link/0,
+    %% process context
+    %% gen_server callbacks
+    init/1, handle_call/3, handle_cast/2, handle_info/2,
+    code_change/3, terminate/2
+]).
+
+-include("$zx_include/zx_logger.hrl").
+
+
+-record(s, {parent :: pid()}).
+
+-type state() :: #s{}.
+
+%%-----------------------------------------------------------------------------
+%% caller context below this line
+%%-----------------------------------------------------------------------------
+
+-spec start_link() -> {ok, pid()} | {error, term()}.
+start_link() ->
+    gen_server:start_link(?MODULE, [self()], []).
+
+
+%%-----------------------------------------------------------------------------
+%% process context below this line
+%%-----------------------------------------------------------------------------
+
+%% gen_server callbacks
+
+-spec init(Args) -> {ok, State}
+    when Args   :: [Parent],
+         Parent :: pid(),
+         State  :: state().
+
+init([Parent]) ->
+    tell("~tp:~tp starting fd_tetris with parent ~p", [?MODULE, self(), Parent]),
+    self() ! {poop, 0},
+    InitState = #s{parent = Parent},
+    {ok, InitState}.
+
+
+handle_call(Unexpected, From, State) ->
+    tell("~tp:~tp unexpected call from ~tp: ~tp", [?MODULE, self(), From, Unexpected]),
+    {noreply, State}.
+
+
+handle_cast(Unexpected, State) ->
+    tell("~tp:~tp unexpected cast: ~tp", [?MODULE, self(), Unexpected]),
+    {noreply, State}.
+
+
+handle_info({poop, N}, State = #s{parent = Parent}) ->
+    Parent ! {tetris, io_lib:format("poop~p", [N])},
+    erlang:send_after(1_000, self(), {poop, N+1}),
+    {noreply, State};
+handle_info(Unexpected, State) ->
+    tell("~tp:~tp unexpected info: ~tp", [?MODULE, self(), Unexpected]),
+    {noreply, State}.
+
+
+code_change(_, State, _) ->
+    {ok, State}.
+
+terminate(_, _) ->
+    ok.