diff --git a/FENTESTS.txt b/FENTESTS.txt
index cc19f35..0249c43 100644
--- a/FENTESTS.txt
+++ b/FENTESTS.txt
@@ -1,8 +1,12 @@
-'4k3/4p3/8/b7/1BR1p2p/1Q3P2/5N2/4K3 w - - 0 1'
-'r1bq1rk1/pppp1ppp/2n2n2/4p3/2B1P3/3PPN2/PPP3PP/RN1QK2R b KQ - 1 7'
-'6k1/6pp/R2p4/p1p5/8/1P1r3P/6P1/6K1 b - - 3 37'
+4k3/4p3/8/b7/1BR1p2p/1Q3P2/5N2/4K3 w - - 0 1
+r1bq1rk1/pppp1ppp/2n2n2/4p3/2B1P3/3PPN2/PPP3PP/RN1QK2R b KQ - 1 7
+6k1/6pp/R2p4/p1p5/8/1P1r3P/6P1/6K1 b - - 3 37
 
 # both can castle queen only
-'r3k2r/8/3B4/8/8/3b4/8/R3K2R w KQkq - 0 1'
-'r3k2r/8/3BB3/8/8/3bb3/8/R3K2R w KQkq - 0 1'
-'r2bkb1r/8/8/8/8/3bb3/8/R2BKB1R w KQkq - 0 1'
+r3k2r/8/3B4/8/8/3b4/8/R3K2R w KQkq - 0 1
+r3k2r/8/3BB3/8/8/3bb3/8/R3K2R w KQkq - 0 1
+r2bkb1r/8/8/8/8/3bb3/8/R2BKB1R w KQkq - 0 1
+
+# illegal positions
+4k3/8/8/8/7b/8/8/4K3 b - - 0 1
+2r1k3/3P4/8/8/8/8/8/4K3 w - - 0 1
diff --git a/make.deps b/make.deps
index caaabb4..f0f3f1d 100644
--- a/make.deps
+++ b/make.deps
@@ -13,4 +13,5 @@
  src/list.h src/pool.h src/board.h src/position.h
 ./obj/pool.o:: src/pool.c src/list.h src/pool.h src/debug.h
 ./obj/position.o:: src/position.c src/chessdefs.h src/bits.h src/debug.h \
- src/position.h src/board.h src/piece.h src/list.h src/pool.h src/fen.h
+ src/position.h src/board.h src/piece.h src/list.h src/pool.h src/move.h \
+ src/fen.h
diff --git a/src/bodichess.c b/src/bodichess.c
index c8e213a..8f7820f 100644
--- a/src/bodichess.c
+++ b/src/bodichess.c
@@ -48,13 +48,15 @@ COMMAND *find_command (char *);
 char *stripwhite (char *string);
 
 /* The names of functions that actually do the manipulation. */
-int do_help (pos_t *, char*);
-int do_fen (pos_t *, char*);
-int do_pos (pos_t *, char*);
+int do_help(pos_t *, char*);
+int do_fen(pos_t *, char*);
+int do_pos(pos_t *, char*);
 int do_genmoves(pos_t *, char*);
 int do_prmoves(pos_t *, char*);
-int do_eval (pos_t *, char*);
-int do_quit (pos_t *, char*);
+int do_memstats(pos_t *, char*);
+int do_eval(pos_t *, char*);
+int do_quit(pos_t *, char*);
+int do_debug(pos_t *, char*);
 
 COMMAND commands[] = {
     { "help", do_help, "Display this text" },
@@ -62,10 +64,12 @@ COMMAND commands[] = {
     { "fen", do_fen, "Set position to FEN" },
     { "pos", do_pos, "Print current position" },
     { "quit", do_quit, "Quit" },
-    { "genmv", do_genmoves, "Generate next move list" },
-    { "prmv", do_prmoves, "Generate next move list" },
+    { "genmove", do_genmoves, "Generate next move list" },
+    { "prmoves", do_prmoves, "Generate next move list" },
+    { "memstats", do_memstats, "Generate next move list" },
     { "eval", do_eval, "Eval current position" },
-    { NULL, (int (*)()) NULL, NULL }
+    { "debug", do_debug, "Set log level to LEVEL" },
+    { NULL, (int(*)()) NULL, NULL }
 };
 
 static int done=0;
@@ -87,13 +91,13 @@ int bodichess(pos_t *pos)
          * Then, if there is anything left, add it to the history list
          * and execute it.
          */
-        s = stripwhite (buffer);
+        s = stripwhite(buffer);
 
         if (*s) {
-            add_history (s);
-            execute_line (pos, s);
+            add_history(s);
+            execute_line(pos, s);
         }
-        free (buffer);
+        free(buffer);
     }
 
     return 0;
@@ -170,15 +174,13 @@ char *escape(const char *original)
 
 int quote_detector(char *line, int index)
 {
-    return (
-        index > 0 &&
-        line[index - 1] == '\\' &&
-        !quote_detector(line, index - 1)
-        );
+    return index > 0
+            && line[index - 1] == '\\'
+            &&!quote_detector(line, index - 1);
 }
 
 /* Execute a command line. */
-int execute_line (pos_t *pos, char *line)
+int execute_line(pos_t *pos, char *line)
 {
     register int i;
     COMMAND *command;
@@ -186,31 +188,31 @@ int execute_line (pos_t *pos, char *line)
 
     /* Isolate the command word. */
     i = 0;
-    while (line[i] && whitespace (line[i]))
+    while (line[i] && whitespace(line[i]))
         i++;
     word = line + i;
 
-    while (line[i] && !whitespace (line[i]))
+    while (line[i] && !whitespace(line[i]))
         i++;
 
     if (line[i])
         line[i++] = '\0';
 
-    command = find_command (word);
+    command = find_command(word);
 
     if (!command) {
-        fprintf (stderr, "%s: Unknown command.\n", word);
-        return (-1);
+        fprintf(stderr, "%s: Unknown command.\n", word);
+        return -1;
     }
 
     /* Get argument to command, if any. */
-    while (whitespace (line[i]))
+    while (whitespace(line[i]))
         i++;
 
     word = line + i;
 
     /* return command number */
-    return ((*(command->func)) (pos, word));
+    return (*command->func)(pos, word);
 }
 
 /* Look up NAME as the name of a command, and return a pointer to that
@@ -220,10 +222,10 @@ COMMAND *find_command(char *name)
     register int i;
 
     for (i = 0; commands[i].name; i++)
-        if (strcmp (name, commands[i].name) == 0)
-            return (&commands[i]);
+        if (strcmp(name, commands[i].name) == 0)
+            return &commands[i];
 
-    return ((COMMAND *)NULL);
+    return (COMMAND *)NULL;
 }
 
 /* Strip whitespace from the start and end of STRING.  Return a pointer
@@ -232,14 +234,14 @@ char *stripwhite(char *string)
 {
     register char *s, *t;
 
-    for (s = string; whitespace (*s); s++)
+    for (s = string; whitespace(*s); s++)
         ;
 
     if (*s == 0)
-        return (s);
+        return s;
 
-    t = s + strlen (s) - 1;
-    while (t > s && whitespace (*t))
+    t = s + strlen(s) - 1;
+    while (t > s && whitespace(*t))
         t--;
     *++t = '\0';
 
@@ -261,7 +263,7 @@ int do_fen(pos_t *pos, char *arg)
     return 1;
 }
 
-int do_pos (pos_t *pos,
+int do_pos(pos_t *pos,
             __attribute__((unused)) char *arg)
 {
     log_f(1, "%s\n", arg);
@@ -286,12 +288,28 @@ int do_prmoves(pos_t *pos,
     return 1;
 }
 
+int do_memstats(__attribute__((unused)) pos_t *pos,
+               __attribute__((unused)) char *arg)
+{
+    moves_pool_stats();
+    piece_pool_stats();
+    pos_pool_stats();
+    return 1;
+}
+
 int do_quit(__attribute__((unused)) pos_t *pos,
             __attribute__((unused)) char *arg)
 {
     return done = 1;
 }
 
+int do_debug(__attribute__((unused)) pos_t *pos,
+            __attribute__((unused)) char *arg)
+{
+    debug_level_set(atoi(arg));
+    return 1;
+}
+
 /* Print out help for ARG, or for all of the commands if ARG is
    not present. */
 int do_help(__attribute__((unused)) pos_t *pos,
@@ -301,30 +319,30 @@ int do_help(__attribute__((unused)) pos_t *pos,
     int printed = 0;
 
     for (i = 0; commands[i].name; i++) {
-        if (!*arg || (strcmp (arg, commands[i].name) == 0)) {
-            printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
+        if (!*arg || (strcmp(arg, commands[i].name) == 0)) {
+            printf("%s\t\t%s.\n", commands[i].name, commands[i].doc);
             printed++;
         }
     }
 
     if (!printed) {
-        printf ("No commands match `%s'.  Possibilties are:\n", arg);
+        printf("No commands match `%s'.  Possibilties are:\n", arg);
 
         for (i = 0; commands[i].name; i++) {
             /* Print in six columns. */
             if (printed == 6) {
                 printed = 0;
-                printf ("\n");
+                printf("\n");
             }
 
-            printf ("%s\t", commands[i].name);
+            printf("%s\t", commands[i].name);
             printed++;
         }
 
         if (printed)
-            printf ("\n");
+            printf("\n");
     }
-    return (0);
+    return 0;
 }
 
 #ifdef BIN_bodichess
diff --git a/src/fen.c b/src/fen.c
index 3f730a9..7b8d550 100644
--- a/src/fen.c
+++ b/src/fen.c
@@ -53,6 +53,7 @@ pos_t *fen2pos(pos_t *pos, char *fen)
     board_t *board = pos->board;
 #   define SKIP_BLANK(p) for(;*(p) == ' '; (p)++)
 
+    pos_clear(pos);
     /* 1) get piece placement information
      */
     for (rank = 7, file = 0; *p && *p != ' '; ++p) {
diff --git a/src/move.c b/src/move.c
index 01e7b8a..290b98a 100644
--- a/src/move.c
+++ b/src/move.c
@@ -54,6 +54,12 @@ pool_t *moves_pool_init()
     return moves_pool;
 }
 
+void moves_pool_stats()
+{
+    if (moves_pool)
+        pool_stats(moves_pool);
+}
+
 int move_print(move_t *move, move_flags_t flags)
 {
     if (flags & M_PR_CAPT && !(move->flags & M_CAPTURE)) {
@@ -141,8 +147,17 @@ static move_t *move_add(pos_t *pos, piece_t piece, square_t from,
           FILE2C(GET_F(to)),
           RANK2C(GET_R(to)));
 #   endif
+    /* impossible if opponent king is attacked
+     */
     if (COLOR(piece) != pos->turn)
         return NULL;
+    if (board[to].piece & KING) {
+#       ifdef DEBUG_MOVE
+        log_i(2, "invalid position: opponent king [%c%c] is in check.\n",
+              FILE2C(GET_F(to)), RANK2C(GET_R(to)));
+#       endif
+        return NULL;
+    }
     if (!(move = pool_get(moves_pool)))
         return NULL;
 
@@ -165,6 +180,42 @@ static move_t *move_add(pos_t *pos, piece_t piece, square_t from,
     return move;
 }
 
+void move_del(struct list_head *ptr)
+{
+    move_t *move = list_entry(ptr, move_t, list);
+
+#   ifdef DEBUG_MOVE
+    log_i(3, "delete move from %c%c to %c%c\n",
+          FILE2C(GET_F(move->from)), RANK2C(GET_R(move->from)),
+          FILE2C(GET_F(move->to)), RANK2C(GET_R(move->to)));
+#   endif
+
+    /* TODO: remove move->pos if non null */
+    if (move->pos) {
+        pos_clear(move->pos);
+    }
+    list_del(ptr);
+    pool_add(moves_pool, move);
+    return;
+}
+
+int moves_del(pos_t *pos)
+{
+    struct list_head *p_cur, *tmp, *head;
+    int count = 0;
+
+    head = &pos->moves;
+
+    list_for_each_safe(p_cur, tmp, head) {
+        move_del(p_cur);
+        count++;
+    }
+#   ifdef DEBUG_PIECE
+    log_f(3, "removed=%d\n", count);
+#   endif
+    return count;
+}
+
 /* TODO: return nmoves */
 static move_t *move_pawn_add(pos_t *pos, piece_t piece, square_t from,
                              square_t to, unsigned char rank7)
@@ -217,7 +268,7 @@ int pseudo_moves_pawn(pos_t *pos, piece_list_t *ppiece, bool doit)
     }
 
 #   ifdef DEBUG_MOVE
-    log_f(3, "pos:%p turn:%s piece:%d [%s %s] dir:%d at %#04x[%c%c]\n",
+    log_f(2, "pos:%p turn:%s piece:%d [%s %s] dir:%d at %#04x[%c%c]\n",
           pos,
           IS_WHITE(pos->turn)? "white": "black",
           piece,
@@ -464,6 +515,7 @@ int moves_gen(pos_t *pos, bool color, bool doit)
     if (doit)
         pseudo_moves_castle(pos);
     list_for_each_safe(p_cur, tmp, piece_list) {
+
         piece = list_entry(p_cur, piece_list_t, list);
         if (PIECE(piece->piece) != PAWN)
             pseudo_moves_gen(pos, piece, doit);
diff --git a/src/move.h b/src/move.h
index c7dd420..b769ce8 100644
--- a/src/move.h
+++ b/src/move.h
@@ -19,10 +19,6 @@
 #include "pool.h"
 #include "piece.h"
 
-/* move_add() return value when generating
- */
-
-
 /* move flags
  */
 typedef unsigned char move_flags_t;
@@ -48,14 +44,18 @@ typedef struct move_s {
     piece_t promotion;                            /* promoted piece */
     move_flags_t flags;
     struct list_head list;                        /* next move */
-    struct pos_t *pos;                            /* resulting position */
+    struct pos_s *pos;                            /* resulting position */
 } move_t;
 
 pool_t *moves_pool_init();
+void moves_pool_stats();
 int move_print(move_t *move, move_flags_t flags);
 void moves_print(pos_t *move, move_flags_t flags);
 int pseudo_moves_castle(pos_t *pos);
 
+void move_del(struct list_head *ptr);
+int moves_del(pos_t *pos);
+
 int pseudo_moves_gen(pos_t *pos, piece_list_t *piece, bool doit);
 int pseudo_moves_pawn(pos_t *pos, piece_list_t *piece, bool doit);
 int moves_gen(pos_t *pos, bool color, bool doit);
diff --git a/src/piece.c b/src/piece.c
index 8e777fb..8ab3376 100644
--- a/src/piece.c
+++ b/src/piece.c
@@ -54,6 +54,12 @@ pool_t *piece_pool_init()
     return pieces_pool;
 }
 
+void piece_pool_stats()
+{
+    if (pieces_pool)
+        pool_stats(pieces_pool);
+}
+
 static eval_t pieces_values[] = {
     [PAWN] = PAWN_VALUE,
     [KNIGHT] = KNIGHT_VALUE,
@@ -85,6 +91,34 @@ piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square)
     return new;
 }
 
+void piece_del(struct list_head *ptr)
+{
+    piece_list_t *piece = list_entry(ptr, piece_list_t, list);
+#   ifdef DEBUG_PIECE
+    log_f(3, "piece=%02x square=%02x\n", piece->piece, piece->square);
+#   endif
+    list_del(ptr);
+    pool_add(pieces_pool, piece);
+    return;
+}
+
+int pieces_del(pos_t *pos, short color)
+{
+    struct list_head *p_cur, *tmp, *head;
+    int count = 0;
+
+    head = &pos->pieces[color];
+
+    list_for_each_safe(p_cur, tmp, head) {
+        piece_del(p_cur);
+        count++;
+    }
+#   ifdef DEBUG_PIECE
+    log_f(3, "color=%d removed=%d\n", color, count);
+#   endif
+    return count;
+}
+
 #ifdef BIN_piece
 #include "fen.h"
 int main(int ac, char**av)
diff --git a/src/piece.h b/src/piece.h
index 4e28b2a..096d7e3 100644
--- a/src/piece.h
+++ b/src/piece.h
@@ -62,6 +62,9 @@ extern struct piece_details {
 
 void piece_list_print(struct list_head *list);
 pool_t *piece_pool_init();
+void piece_pool_stats();
 piece_list_t *piece_add(pos_t *pos, piece_t piece, square_t square);
+void piece_del(struct list_head *ptr);
+int pieces_del(pos_t *pos, short color);
 
 #endif
diff --git a/src/position.c b/src/position.c
index 426eef2..9c3ed7b 100644
--- a/src/position.c
+++ b/src/position.c
@@ -19,6 +19,7 @@
 
 #include "chessdefs.h"
 #include "position.h"
+#include "move.h"
 #include "fen.h"
 #include "piece.h"
 
@@ -149,9 +150,10 @@ pos_t *pos_clear(pos_t *pos)
     pos->controlled[BLACK] = 0;
     pos->mobility[WHITE] = 0;
     pos->mobility[BLACK] = 0;
-    INIT_LIST_HEAD(&pos->pieces[WHITE]);
-    INIT_LIST_HEAD(&pos->pieces[BLACK]);
-    INIT_LIST_HEAD(&pos->moves);
+    /* remove pieces / moves */
+    pieces_del(pos, WHITE);
+    pieces_del(pos, BLACK);
+    moves_del(pos);
 
     return pos;
 }
@@ -167,15 +169,10 @@ pos_t *pos_get()
 {
     pos_t *pos = pool_get(pos_pool);
     if (pos) {
-        //printf("sizeof(board)=%lu\n", sizeof (board_t));
-        //pos->board = malloc(sizeof (board_t)*BOARDSIZE);
-        //printf("board mem: %p-%p\n", pos->board, pos->board+sizeof (board_t));
-        //if (pos->board)
+        INIT_LIST_HEAD(&pos->pieces[WHITE]);
+        INIT_LIST_HEAD(&pos->pieces[BLACK]);
+        INIT_LIST_HEAD(&pos->moves);
         pos_clear(pos);
-        //else {
-        //    free(pos);
-        //    pos = NULL;
-        //}
     }
     return pos;
 }
@@ -207,3 +204,9 @@ pool_t *pos_pool_init()
         pos_pool = pool_init("positions", 128, sizeof(pos_t));
     return pos_pool;
 }
+
+void pos_pool_stats()
+{
+    if (pos_pool)
+        pool_stats(pos_pool);
+}
diff --git a/src/position.h b/src/position.h
index 8378c7a..5bf0da0 100644
--- a/src/position.h
+++ b/src/position.h
@@ -45,6 +45,7 @@ pos_t *pos_clear(pos_t *pos);
 pos_t *pos_startpos(pos_t *pos);
 pos_t *pos_create();
 pool_t *pos_pool_init();
+void pos_pool_stats();
 pos_t *pos_get();
 pos_t *pos_dup(pos_t *pos);