Translate the following question to SQL: Count the number of distinct player positions.

Schema: CREATE TABLE school (
    School_ID INT   PRIMARY KEY,
    School TEXT,
    Location TEXT,
    Enrollment REAL,
    Founded REAL,
    Denomination TEXT,
    Boys_or_Girls TEXT,
    Day_or_Boarding TEXT,
    Year_Entered_Competition REAL,
    School_Colors TEXT,
    UNIQUE (School_ID)
);

CREATE TABLE school_details (
    School_ID INT   PRIMARY KEY,
    Nickname TEXT,
    Colors TEXT,
    League TEXT,
    Class TEXT,
    Division TEXT,
    UNIQUE (School_ID),
    FOREIGN KEY (School_ID) REFERENCES school(School_ID)
);

CREATE TABLE school_performance (
    School_Id INT   PRIMARY KEY,
    School_Year TEXT   PRIMARY KEY,
    Class_A TEXT,
    Class_AA TEXT,
    PRIMARY KEY (School_Id, School_Year),
    UNIQUE (School_Id, School_Year),
    FOREIGN KEY (School_Id) REFERENCES school(School_ID)
);

CREATE TABLE player (
    Player_ID INT   PRIMARY KEY,
    Player TEXT,
    Team TEXT,
    Age INT,
    Position TEXT,
    School_ID INT,
    UNIQUE (Player_ID),
    FOREIGN KEY (School_ID) REFERENCES school(School_ID)
);
user
SELECT count(DISTINCT POSITION) FROM player
assistant