user16705: If the knight moves then is it possible to give check mate? I have already given one check. I was playing a game of "3 check". How can I get two more checks? Is it not possible?
3 check is a mode in chess where you have to give 3 checks. Here in this game I gave one check before. At move 16 the black side made a mistake. Would it have been  possible to give two more checks if the black side hadn't made that mistake? Black also has two checks left.
https://www.chess.com/live/game/3016880533
[FEN ""]
[Event "Live Chess - Three-Check"]
[Site "Chess.com"]
[Date "2018.08.19"]
[White "RuhanUR"]
[Black "PAM_Andrei"]
[Result "1-0"]
[ECO "A00"]
[WhiteElo "1060"]
[BlackElo "794"]
[TimeControl "300"]
[EndTime "8:26:19 PDT"]
[Termination "RuhanUR won by checking the opponent king for the 3rd time"]
[Variant "Three-Check"]
[CurrentPosition "r2q1r1k/pp2b2Q/8/2p1p3/6bP/1P4Pn/P1P2P2/R1B2R1K b - - 0 21 +3+1"]

1.Nc3 {[%clk 0:04:56]} e6 {[%clk 0:04:57]} 2.Ne4 {[%clk 0:04:44]} c5 {[%clk 0:04:54]} 3.Nd6+ {[%clk 0:04:43]} Bxd6 {[%clk 0:04:51]} 4.g3 {[%clk 0:04:35]} Nc6 {[%clk 0:04:46]} 5.Bh3 {[%clk 0:04:34]} Nf6 {[%clk 0:04:43]} 6.d3 {[%clk 0:04:18]} O-O {[%clk 0:04:41]} 7.Nf3 {[%clk 0:04:01]} e5 {[%clk 0:04:26]} 8.Bf5 {[%clk 0:03:51]} g6 {[%clk 0:04:22]} 9.Bxg6 {[%clk 0:03:26]} fxg6 {[%clk 0:04:18]} 10.Ng5 {[%clk 0:03:18]} Nd4 {[%clk 0:04:05]} 11.O-O {[%clk 0:02:56]} Be7 {[%clk 0:03:59]} 12.e3 {[%clk 0:02:51]} Ne6 {[%clk 0:03:54]} 13.Nxh7 {[%clk 0:02:49]} Nxh7 {[%clk 0:03:51]} 14.e4 {[%clk 0:02:38]} Neg5 {[%clk 0:03:47]} 15.b3 {[%clk 0:02:16]} d5 {[%clk 0:03:45]} 16.h4 {[%clk 0:01:56]} Nh3+ {[%clk 0:03:31]} 17.Kg2 {[%clk 0:01:38]} dxe4 {[%clk 0:03:29]} 18.Kh1 {[%clk 0:01:08]} exd3 {[%clk 0:03:24]} 19.Qxd3 {[%clk 0:01:04]} Bg4 {[%clk 0:03:06]} 20.Qxg6+ {[%clk 0:00:54]} Kh8 {[%clk 0:03:00]} 21.Qxh7+ {[%clk 0:00:47]}  1-0

Go to move 16. What if my opponent hadn't made a mistake, then how could I have won?

user17202: After 16. h4, there is no way for you to win this position, as black has a forced win in 4 moves.

..Nh3+ is not a mistake by black, in fact it is winning. After your move 17. Kg2, black wins the game with 17. ..Rf2+ 18. Rxf2 Nf4+ 0-1.

If you look at Fabian's link, you can see that black has a forced win in 5 as early as move 15.
So, to answer your question: No, it is not possible for you to give 2 more checks.

user15415: Black's decisive mistake was 19...Bg4, up to there he was winning. You can analyze three-check chess games online on lichess, or using multi-variant Stockfish offline with a GUI supporting chess variants (e.g., WinBoard/XBoard, PyChess, CuteChess, etc.).
I imported your game to lichess and triggered the automatic analysis, see https://lichess.org/uUVDe8ei#38.

16705: <p>If the knight moves then is it possible to give check mate? I have already given one check. I was playing a game of "3 check". How can I get two more checks? Is it not possible?</p>

<p><em>3 check is a mode in chess where you have to give 3 checks. Here in this game I gave one check before. At move 16 the black side made a mistake. Would it have been  possible to give two more checks if the black side hadn't made that mistake? Black also has two checks left.</em></p>

<p><a href="https://www.chess.com/live/game/3016880533" rel="nofollow noreferrer">https://www.chess.com/live/game/3016880533</a></p>

<pre><code>[FEN ""]
[Event "Live Chess - Three-Check"]
[Site "Chess.com"]
[Date "2018.08.19"]
[White "RuhanUR"]
[Black "PAM_Andrei"]
[Result "1-0"]
[ECO "A00"]
[WhiteElo "1060"]
[BlackElo "794"]
[TimeControl "300"]
[EndTime "8:26:19 PDT"]
[Termination "RuhanUR won by checking the opponent king for the 3rd time"]
[Variant "Three-Check"]
[CurrentPosition "r2q1r1k/pp2b2Q/8/2p1p3/6bP/1P4Pn/P1P2P2/R1B2R1K b - - 0 21 +3+1"]

1.Nc3 {[%clk 0:04:56]} e6 {[%clk 0:04:57]} 2.Ne4 {[%clk 0:04:44]} c5 {[%clk 0:04:54]} 3.Nd6+ {[%clk 0:04:43]} Bxd6 {[%clk 0:04:51]} 4.g3 {[%clk 0:04:35]} Nc6 {[%clk 0:04:46]} 5.Bh3 {[%clk 0:04:34]} Nf6 {[%clk 0:04:43]} 6.d3 {[%clk 0:04:18]} O-O {[%clk 0:04:41]} 7.Nf3 {[%clk 0:04:01]} e5 {[%clk 0:04:26]} 8.Bf5 {[%clk 0:03:51]} g6 {[%clk 0:04:22]} 9.Bxg6 {[%clk 0:03:26]} fxg6 {[%clk 0:04:18]} 10.Ng5 {[%clk 0:03:18]} Nd4 {[%clk 0:04:05]} 11.O-O {[%clk 0:02:56]} Be7 {[%clk 0:03:59]} 12.e3 {[%clk 0:02:51]} Ne6 {[%clk 0:03:54]} 13.Nxh7 {[%clk 0:02:49]} Nxh7 {[%clk 0:03:51]} 14.e4 {[%clk 0:02:38]} Neg5 {[%clk 0:03:47]} 15.b3 {[%clk 0:02:16]} d5 {[%clk 0:03:45]} 16.h4 {[%clk 0:01:56]} Nh3+ {[%clk 0:03:31]} 17.Kg2 {[%clk 0:01:38]} dxe4 {[%clk 0:03:29]} 18.Kh1 {[%clk 0:01:08]} exd3 {[%clk 0:03:24]} 19.Qxd3 {[%clk 0:01:04]} Bg4 {[%clk 0:03:06]} 20.Qxg6+ {[%clk 0:00:54]} Kh8 {[%clk 0:03:00]} 21.Qxh7+ {[%clk 0:00:47]}  1-0
</code></pre>

<p><em>Go to move 16. What if my opponent hadn't made a mistake, then how could I have won?</em></p>
 17202: <p>After 16. h4, there is no way for you to win this position, as black has a forced win in 4 moves.</p>

<ol start="16">
<li>..Nh3+ is not a mistake by black, in fact it is winning. After your move 17. Kg2, black wins the game with 17. ..Rf2+ 18. Rxf2 Nf4+ 0-1.</li>
</ol>

<p>If you look at Fabian's link, you can see that black has a forced win in 5 as early as move 15.</p>

<p>So, to answer your question: No, it is not possible for you to give 2 more checks.</p>
 15415: <p>Black's decisive mistake was 19...Bg4, up to there he was winning. You can analyze three-check chess games online on <a href="https://lichess.org/" rel="nofollow noreferrer">lichess</a>, or using <a href="https://github.com/ddugovic/Stockfish" rel="nofollow noreferrer">multi-variant Stockfish</a> offline with a GUI supporting chess variants (e.g., WinBoard/XBoard, PyChess, CuteChess, etc.).</p>

<p>I imported your game to lichess and triggered the automatic analysis, see <a href="https://lichess.org/uUVDe8ei#38" rel="nofollow noreferrer">https://lichess.org/uUVDe8ei#38</a>.</p>
