yep

Shogi.Database/Session/Stored Procedures/CreateBoardState.sql

@@ -1,16 +0,0 @@
-CREATE PROCEDURE [dbo].[CreateBoardState]
-	@boardStateDocument NVARCHAR(max),
-	@sessionName NVARCHAR(100)
-AS
-BEGIN
-
-SET NOCOUNT ON
-
-INSERT INTO [session].[BoardState] (Document, SessionId)
-	SELECT 
-		@boardStateDocument, 
-		Id
-	FROM [session].[Session]
-	WHERE [Name] = @sessionName;
-
-END

Shogi.Database/Session/Stored Procedures/CreateSession.sql

@@ -1,6 +1,7 @@
 CREATE PROCEDURE [session].[CreateSession]
-	@InitialBoardStateDocument [session].[JsonDocument],
-	@Player1Name [user].[UserName]
+	@Name [session].[SessionName],
+	@Player1Name [user].[UserName],
+	@InitialBoardStateDocument [session].[JsonDocument]
 AS
 BEGIN
 	SET NOCOUNT ON

Shogi.Database/Session/Tables/Session.sql

@@ -1,17 +1,17 @@
 CREATE TABLE [session].[Session]
 (
 	Id			BIGINT NOT NULL PRIMARY KEY IDENTITY,
-	Created		DATETIMEOFFSET NOT NULL DEFAULT SYSDATETIMEOFFSET(),
+	[Name]		[session].[SessionName] UNIQUE,
 	Player1Id	BIGINT NOT NULL,
 	Player2Id	BIGINT NULL,
 	BoardState	[session].[JsonDocument] NOT NULL,
-	[Name]		AS JSON_VALUE(BoardState, '$.Name') UNIQUE,
+	Created		DATETIMEOFFSET NOT NULL DEFAULT SYSDATETIMEOFFSET(),
 
 	CONSTRAINT [BoardState must be json] CHECK (isjson(BoardState)=1),
-	CONSTRAINT FK_Player1_User FOREIGN KEY (Player1Id) REFERENCES [user].[User] (Id) 
-		ON DELETE CASCADE 
+	CONSTRAINT FK_Player1_User FOREIGN KEY (Player1Id) REFERENCES [user].[User] (Id)
+		ON DELETE CASCADE
 		ON UPDATE CASCADE,
-	CONSTRAINT FK_Player2_User FOREIGN KEY (Player2Id) REFERENCES [user].[User] (Id) 
+	CONSTRAINT FK_Player2_User FOREIGN KEY (Player2Id) REFERENCES [user].[User] (Id)
 		ON DELETE NO ACTION
 		ON UPDATE NO ACTION
 )

Shogi.Database/Shogi.Database.sqlproj

@@ -72,7 +72,6 @@
     <Build Include="User\user.sql" />
     <Build Include="Session\Tables\Session.sql" />
     <Build Include="Session\Stored Procedures\CreateSession.sql" />
-    <Build Include="Session\Stored Procedures\CreateBoardState.sql" />
     <Build Include="User\Tables\User.sql" />
     <Build Include="Session\Types\SessionName.sql" />
     <Build Include="User\Types\UserName.sql" />